Engine - Wacker Neuson

Transcription

www.wackergroup.com
0160157en
0207
Engine
WM 90
REPAIR MANUAL
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WM 90 Repair
Foreword
Operating / Parts Information
You must be familiar with the operation of this machine before you
attempt to troubleshoot or repair it. Basic operating and maintenance
procedures are described in the Operator’s Manual supplied with the
machine. Keep a copy of the Operator’s Manual with the machine at all
times. Use the separate Parts Book supplied with the machine to order
replacement parts. If you are missing either of the documents, please
contact Wacker Corporation to order a replacement.
Damage caused by misuse or neglect of the unit should be brought to
the attention of the operator to prevent similar occurrences from
happening in the future.
This manual provides information and procedures to safely repair and
maintain the above Wacker model(s). For your own safety and
protection from injury, carefully read, understand, and observe all
instructions described in this manual. THE INFORMATION
CONTAINED IN THIS MANUAL IS BASED ON MACHINES
MANUFACTURED UP TO THE TIME OF PUBLICATION. WACKER
CORPORATION RESERVES THE RIGHT TO CHANGE ANY
PORTION OF THIS INFORMATION WITHOUT NOTICE.
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Foreword
WARNING
WM 90 Repair
CALIFORNIA
Proposition 65 Warning:
Engine exhaust, some of its constituents, and certain vehicle
components, contain or emit chemicals known to the State of
California to cause cancer and birth defects or other reproductive
harm.
Laws Pertaining to Spark Arresters
Notice: State Health Safety Codes and Public Resources Codes
specify that in certain locations spark arresters be used on internal
combustion engines that use hydrocarbon fuels. A spark arrester is a
device designed to prevent accidental discharge of sparks or flames
from the engine exhaust. Spark arresters are qualified and rated by
the United States Forest Service for this purpose.
In order to comply with local laws regarding spark arresters, consult
the engine distributor or the local Health and Safety Administrator.
All rights, especially copying and distribution rights, are reserved.
Copyright 2007 by Wacker Corporation
No part of this publication may be reproduced in any form or by any
means, electronic or mechanical, including photocopying, without
express written permission from Wacker Corporation.
Any type of reproduction or distribution not authorized by Wacker
Corporation represents an infringement of valid copyrights, and
violators will be prosecuted. We expressly reserve the right to make
technical modifications, even without due notice, which aim at
improving our machines or their safety standards.
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WM 90 Repair
Table of Contents
1.
Emission Control System Information
2.
Safety Information
2.1
2.2
2.3
2.4
2.5
2.6
3.
4.
Operating Safety ................................................................................ 14
Operator Safety while using Internal Combustion Engines ................ 15
Service Safety .................................................................................... 16
Label Locations .................................................................................. 17
Safety Labels ...................................................................................... 18
Operating Labels ................................................................................ 21
23
Specifications ..................................................................................... 23
Performance ....................................................................................... 24
Theory of Operation
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
5.
13
Technical Data
3.1
3.2
25
Application .......................................................................................... 25
Recommended Fuel ........................................................................... 25
Before Starting ................................................................................... 25
To Start ............................................................................................... 26
To Stop ............................................................................................... 27
Component Descriptions .................................................................. 27
Cross Section Across Shaft ................................................................ 32
Cross Section Across Shaft Components .......................................... 33
Cross Section Along Shaft ................................................................. 34
Cross Section Along Shaft Components ............................................ 35
Maintenance
5.1
5.2
5.3
5.4
8
36
Periodic Maintenance Schedule ......................................................... 36
Servicing Air Cleaner .......................................................................... 37
Servicing Fuel Filter and Fuel Tank .................................................... 38
Long-Term Storage ............................................................................ 39
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Table of Contents
6.
Dissassembly/Reassembly General Information
6.1
6.2
6.3
6.4
7.
41
Removing Engine from Rammer .........................................................41
Draining Oil ..........................................................................................43
Removing Recoil Starter and Blower Housing ....................................44
Removing Muffler ................................................................................45
Removing Governor Lever, Carburetor, Speed Control Lever ............46
Removing Ignition Coil, Flywheel, and Spark Plug ..............................47
Removing Rocker Cover and Cylinder Head ......................................48
Removing Bearing Cover ....................................................................49
Removing Camshaft and Tappets .......................................................50
Removing Connecting Rod and Piston ...............................................51
Removing Crankshaft ..........................................................................52
Removing Intake and Exhaust Valves .................................................53
Reassembly Procedures
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
8.10
8.11
8.12
8.13
8.14
8.15
40
Tools ....................................................................................................40
Ordering Parts .....................................................................................40
Reference Numbers ( ) ........................................................................40
Weight Block .......................................................................................40
Disassembly Procedures
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
7.11
7.12
8.
WM 90 Repair
54
Notes on Reassembly .........................................................................54
Crankshaft ...........................................................................................54
Reassembling Piston ...........................................................................55
Reassembling Piston and Connecting Rod .........................................56
Installing Piston ...................................................................................57
Installing Tappets and Camshaft .........................................................58
Adjusting Crankshaft End Play ............................................................59
Installing Main Bearing Cover .............................................................60
Cylinder Head ......................................................................................61
Reassembling Rocker Arms and Push Rods ......................................62
Adjusting Valve Clearances ................................................................63
Installing Rocker Cover and Spark Plug ..............................................64
Installing Flywheel Magneto ................................................................65
Installing Ignition Coil ..........................................................................65
Installing Governor, Speed Control System, and Carburetor ..............66
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WM 90 Repair
8.16
8.17
8.18
8.19
8.20
9.
Table of Contents
Adjusting Governor System ................................................................ 67
Installing Muffler ................................................................................. 67
Installing Blower Housing and Recoil Starter ..................................... 68
Re-installing Engine ........................................................................... 69
Break-in Operation ............................................................................. 71
Sub Systems
9.1
9.2
9.3
9.4
9.5
9.6
9.7
9.8
9.9
72
Magneto ............................................................................................. 72
Engine Basic Electric Theory ............................................................. 72
Electrical Components ....................................................................... 73
Automatic Decompression System .................................................... 74
Diaphragm-Type Carburetor .............................................................. 75
Carburetor Disassembly Procedure ................................................... 78
Carburetor Inspection ......................................................................... 79
Carburetor Reassembly ..................................................................... 79
Carburetor Adjustments ..................................................................... 80
10. Recoil Starter
10.1
10.2
10.3
10.4
10.5
10.6
10.7
81
Recoil Starter Disassembly ................................................................ 81
Checking the Recoil Starter After Reassembly .................................. 85
Starter Assembly Exploded View ....................................................... 86
Disassembling the Starter .................................................................. 87
Inspecting the Starter ......................................................................... 87
Assembling the Starter ....................................................................... 88
Replacing the Starter Rope ................................................................ 89
11. Clearance Data and Limits Table
11.1
Term Descriptions .............................................................................. 91
12. Troubleshooting
12.1
12.2
91
99
Troubleshooting Introduction .............................................................. 99
Troubleshooting Procedures .............................................................. 99
7
1.
Source of Emissions
The combustion process produces carbon monoxide, oxides of
nitrogen, and hydrocarbons. Control of hydrocarbons and oxides of
nitrogen is very important because, under certain conditions, they
react to form photochemical smog when subjected to sunlight. Carbon
monoxide does not react in the same way, but it is toxic.
Wacker utilizes lean carburetor settings and other systems to reduce
the emissions of carbon monoxide, oxides of nitrogen, and
hydrocarbons.
The U.S. and California Clean Air Acts
EPA and California regulations require all manufacturers to furnish
written instructions describing the operation and maintenance of
emission control systems.
The following instructions and procedures must be followed in order to
keep the emissions from your Wacker engine within the emissions
standards.
Tampering and Altering
Tampering with or altering the emission control system may increase
emissions beyond the legal limit. Among those acts that constitute
tampering are:
•Removal or alteration of any part of the intake, fuel, or exhaust
systems.
•Altering or defeating the speed-adjusting mechanism to cause the
engine to operate outside its design parameters.
Problems That May Affect Emissions
If you are aware of any of the following symptoms, have your engine
inspected and repaired by your servicing dealer.
•Hard starting or stalling after starting.
•Rough idle.
•Misfiring or backfiring under load.
•Afterburning (backfiring).
•Black exhaust smoke or high fuel consumption.
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Replacement Parts
The emission control systems on your Wacker engine were designed,
built, and certified to conform with EPA and California emissions
regulations. We recommend the use of genuine Wacker parts
whenever you have maintenance done. These original-design
replacement parts are manufactured to the same standards as the
original parts, so you can be confident of their performance. The use
of replacement parts that are not of the original design and quality may
impair the effectiveness of your emission control system.
A manufacturer of an aftermarket part assumes the responsibility that
the part will not adversely affect emission performance. The
manufacturer or rebuilder of the part must certify that use of the part
will not result in a failure of the engine to comply with emission
regulations.
Maintenance
Follow the maintenance schedule. Remember that this schedule is
based on the assumption that your machine will be used for its
designed purpose. Sustained high-load or high-temperature operation,
or use in unusually wet or dusty conditions, will require more frequent
service.
OXYGENATED FUELS
Some conventional gasolines are being blended with alcohol or an
ether compound. These gasolines are collectively referred to as
oxygenated fuels. To meet clean air standards, some areas of the
United States and Canada use oxygenated fuels to help reduce
emissions.
If you use an oxygenated fuel, be sure it is unleaded and meets the
minimum octane rating requirement.
Before using an oxygenated fuel, try to confirm the fuel’s contents.
Some States / Provinces require this information to be posted on the
pump.
The following are EPA-approved percentages of oxygenates:
ETHANOL - (ethyl or grain alcohol) 10% by volume. You may use
gasoline containing up to 10% ethanol by volume. Gasoline containing
ethanol may be marketed under the name “Gasohol”.
MTBE - (methyl tertiary butyl ether) 15% by volume. You may use
gasoline containing up to 15% MTBE by volume.
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METHANOL - (methyl or wood alcohol) 5% by volume. You may use
gasoline containing up to 5% methanol by volume, as long as it
contains cosolvents and corrosion inhibitors to protect the fuel system.
Gasoline containing more than 5% methanol by volume may cause
starting and/or performance problems. It may also damage metal,
rubber, and plastic parts of your fuel system.
If you notice any undesirable operating symptoms, try another service
station, or switch to another brand of gasoline.
Fuel system damage or performance problems resulting from the use
of an oxygenated fuel containing more than the percentages of
oxygenates mentioned above are not covered under warranty.
EMISSIONS COMPONENT DEFECT WARRANTY COVERAGE
This emission warranty is applicable in all States.
Wacker Corporation, N92 W15000 Anthony Avenue, Menomonee
Falls, WI 53051-1504, (herein "Wacker") warrant(“s”) to the initial retail
purchaser and each subsequent owner, that this non-road engine
(herein "engine") has been designed, built, and equipped to conform
at the time of initial sale to all applicable regulations of the U.S.
Environmental Protection Agency (EPA), and that the engine is free of
defects in materials and workmanship which would cause this engine
to fail to conform with EPA regulations during its warranty period.
For the components listed under PARTS COVERED, the service
dealer authorized by Wacker will, at no cost to you, make the
necessary diagnosis, repair, or replacement necessary to ensure that
the engine complies with applicable U.S. EPA regulations.
EMISSISON COMPONENT DEFECT WARRANTY PERIOD
The warranty period for this engine begins on the date of sale to the
initial purchaser and continues for a period of 2 years.
PARTS COVERED
Listed below are the parts covered by the Emission Components
Defect Warranty. Some of the parts listed below may require
scheduled maintenance and are warranted up to the first scheduled
replacement point for that part.
(1) Fuel Metering System
(i) Carburetor and internal parts (and/or pressure regulator or fuel
injection system).
(ii) Air/fuel ratio feedback and control system, if applicable.
(iii) Cold start enrichment system, if applicable.
(iv) Regulator assembly (gaseous fuel, if applicable) .
(2) Air Induction System
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(i) Intake manifold, if applicable.
(ii) Air filter.
(3) Ignition System
(i) Spark plugs.
(ii) Magneto or electronic ignition system.
(iii) Spark advance/retard system, if applicable.
(4) Exhaust manifold, if applicable
(5) Miscellaneous Items Used in Above Systems
(i) Electronic controls, if applicable.
(ii) Hoses, belts, connectors, and assemblies.
(iii) Filter lock assembly (gaseous fuel, if applicable).
OBTAINING WARRANTY SERVICE
To obtain warranty service, take your engine to the nearest authorized
Wacker service dealer. Bring your sales receipts indicating date of
purchase for this engine. The service dealer authorized by Wacker will
perform the necessary repairs or adjustments within a reasonable
amount of time and furnish you with a copy of the repair order. All parts
and accessories replaced under this warranty become the property of
Wacker.
WHAT IS NOT COVERED
Conditions resulting from tampering, misuse, improper adjustment
(unless they were made by the service dealer authorized by Wacker
during a warranty repair), alteration, accident, failure to use the
recommended fuel and oil, or not performing required maintenance
services.
The replacement parts used for required maintenance services.
Consequential damages such as loss of time, inconvenience, loss of
use of the engine or equipment, etc.
Diagnosis and inspection charges that do not result in warranty-eligible
service being performed.
Any non-authorized replacement part, or malfunction of authorized
parts due to use of non-authorized parts.
OWNER'S WARRANTY RESPONSIBILITIES
As the engine owner, you are responsible for the performance of the
required maintenance listed in your owner's manual. Wacker
recommends that you retain all receipts covering maintenance on your
engine, but Wacker cannot deny warranty solely for the lack of receipts
or for your failure to ensure the performance of all scheduled
maintenance. As the engine owner, you should however be aware that
Wacker may deny warranty coverage if your engine or a part has failed
due to abuse, neglect, improper maintenance or unapproved
modifications.
11
You are responsible for presenting your engine to the nearest service
dealer authorized by Wacker when a problem exists.
If you have any questions regarding your warranty rights and
responsibilities, you should contact the WACKER CORPORATION
Product Support Department (U.S.A. 1-800-770-0957, Canada 1-877977-0775) for the information.
THINGS YOU SHOULD KNOW ABOUT THE EMISSION CONTROL
SYSTEM WARRANTY:
MAINTENANCE AND REPAIRS
You are responsible for the proper maintenance of the engine. You
should keep all receipts and maintenance records covering the
performance of regular maintenance in the event questions arise.
These receipts and maintenance records should be transferred to
each subsequent owner of the engine. Wacker reserves the right to
deny warranty coverage if the engine has not been properly
maintained. Warranty claims will not be denied, however, solely
because of the lack of required maintenance or failure to keep
maintenance records.
MAINTENANCE, REPLACEMENT OR REPAIR OF EMISSION
CONTROL DEVICES AND SYSTEMS MAY BE PERFORMED BY
ANY REPAIR ESTABLISHMENT OR INDIVIDUAL; HOWEVER,
WARRANTY REPAIRS MUST BE PERFORMED BY A SERVICE
DEALER AUTHORIZED BY WACKER. THE USE OF PARTS THAT
ARE NOT EQUIVALENT IN PERFORMANCE AND DURABILITY TO
AUTHORIZED PARTS MAY IMPAIR THE EFFECTIVENESS OF THE
EMISSION CONTROL SYSTEM AND MAY HAVE A BEARING ON
THE OUTCOME OF A WARRANTY CLAIM.
If other than the parts authorized by Wacker are used for maintenance
replacements or for the repair of components affecting emission
control, you should assure yourself that such parts are warranted by
their manufacturer to be equivalent to the parts authorized by Wacker
in their performance and durability.
HOW TO MAKE A CLAIM
All repair qualifying under this limited warranty must be performed by
a service dealer authorized by Wacker. In the event that any emissionrelated part is found to be defective during the warranty period, you
shall notify WACKER CORPORATION Product Support Department
(U.S.A. 1-800-770-0957, Canada 1-877-977-0775) and you will be
advised of the appropriate warranty service dealer or service providers
where the warranty repair can be performed.
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WM 90 Repair
2.
Safety Information
Safety Information
This manual contains DANGER, WARNING, CAUTION, NOTICE and
NOTE callouts which must be followed to reduce the possibility of
personal injury, damage to the equipment, or improper service.
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that follow this
symbol to avoid possible injury or death.
DANGER indicates a hazardous situation which, if not avoided, will
result in death or serious injury.
DANGER
WARNING indicates a hazardous situation which, if not avoided, could
result in death or serious injury.
WARNING
CAUTION indicates a hazardous situation which, if not avoided, could
result in minor or moderate injury.
CAUTION
NOTICE: Used without the safety alert symbol, NOTICE indicates a
hazardous situation which, if not avoided, could result in property
damage.
Note: Contains additional information important to a procedure.
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Safety Information
2.1
WM 90 Repair
Operating Safety
WARNING
Familiarity and proper training are required for the safe operation of
machine. Machines operated improperly or by untrained personnel
can be dangerous. Read the operating instructions contained in both
this manual and the engine manual and familiarize yourself with the
location and proper use of all controls. Inexperienced operators should
receive instruction from someone familiar with the machine before
being allowed to operate it.
2.1.1
NEVER operate this machine in applications for which it is not
intended.
2.1.2
NEVER allow anyone to operate this equipment without proper
training. People operating this equipment must be familiar with the
risks and hazards associated with it.
2.1.3
NEVER touch the engine or muffler while the engine is on or
immediately after it has been turned off. These areas get hot and may
cause burns.
2.1.4
NEVER use accessories or attachments that are not recommended by
Wacker. Damage to equipment and injury to the user may result.
2.1.5
NEVER leave machine running unattended.
2.1.6
NEVER tamper with or disable the function of operating controls.
2.1.7
NEVER use choke to stop engine.
2.1.8
NEVER operate the machine in areas where explosions may occur.
2.1.9
ALWAYS read, understand, and follow procedures in the Operator’s
Manual before attempting to operate the equipment.
2.1.10 ALWAYS be sure that all other persons are at a safe distance from the
machine. Stop the machine if people step into the working area of the
machine.
2.1.11 ALWAYS be sure operator is familiar with proper safety precautions
and operation techniques before using machine.
2.1.12 ALWAYS wear protective clothing appropriate to the job site when
operating equipment.
2.1.13 ALWAYS wear hearing protection when operating equipment.
2.1.14 ALWAYS keep hands, feet, and loose clothing away from moving parts
of the machine.
2.1.15 ALWAYS use common sense and caution when operating the
machine.
2.1.16 ALWAYS be sure the rammer will not tip over, roll, slide, or fall when
not being operated.
2.1.17 ALWAYS turn the engine OFF when the rammer is not being operated.
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WM 90 Repair
Safety Information
2.1.18
ALWAYS guide the rammer in such a way that the operator is not
squeezed between the rammer and solid objects. Special care is
required when working on uneven ground or when compacting coarse
material. Make sure to stand firmly when operating the machine under
such conditions.
2.1.19
ALWAYS operate the rammer in such a way that there is no danger of
it turning over or falling in, when working near the edges of breaks, pits,
slopes, trenches and platforms.
2.1.20
ALWAYS store the equipment properly when it is not being used.
Equipment should be stored in a clean, dry location out of the reach of
children.
2.1.21
ALWAYS close fuel valve on engines equipped with one when
machine is not being operated.
2.1.22
ALWAYS operate machine with all safety devices and guards in place
and in working order. DO NOT modify or defeat safety devices. DO
NOT operate machine if any safety devices or guards are missing or
inoperative.
2.2
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Operator Safety while using Internal Combustion Engines
DANGER
Internal combustion engines present special hazards during operation
and fueling. Read and follow the warning instructions in the engine
owner’s manual and the safety guidelines below. Failure to follow the
warnings and safety guidelines could result in severe injury or death.
2.2.1
DO NOT smoke while operating the machine.
2.2.2
DO NOT smoke when refueling the engine.
2.2.3
DO NOT refuel a hot or running engine.
2.2.4
DO NOT refuel the engine near an open flame.
2.2.5
DO NOT spill fuel when refueling the engine.
2.2.6
DO NOT run the engine near open flames.
2.2.7
DO NOT run the machine indoors or in an enclosed area such as a
deep trench unless adequate ventilation, through such items as
exhaust fans or hoses, is provided. Exhaust gas from the engine
contains poisonous carbon monoxide gas; exposure to carbon
monoxide can cause loss of consciousness and may lead to death.
2.2.8
ALWAYS refill the fuel tank in a well-ventilated area.
2.2.9
ALWAYS replace the fuel tank cap after refueling.
2.2.10
ALWAYS check the fuel lines and the fuel tank for leaks and cracks
before starting the engine. Do not run the machine if fuel leaks are
present or the fuel lines are loose.
15
Safety Information
2.3
WM 90 Repair
Service Safety
WARNING
Poorly maintained machines can become a safety hazard! In order for
the machine to operate safely and properly over a long period of time,
periodic maintenance and occasional repairs are necessary.
2.3.1
DO NOT attempt to clean or service the machine while it is running.
Rotating parts can cause severe injury.
2.3.2
DO NOT operate the machine without an air cleaner.
2.3.3
DO NOT remove air cleaner cover, paper element, or precleaner while
engine is running.
2.3.4
DO NOT alter engine speeds. Run the engine only at speeds specified
in the Technical Data Section.
2.3.5
DO NOT crank a flooded engine with the spark plug removed on
gasoline-powered engines. Fuel trapped in the cylinder will squirt out
the spark plug opening.
2.3.6
DO NOT test for spark on gasoline-powered engines if the engine is
flooded or the smell of gasoline is present. A stray spark could ignite
the fumes.
2.3.7
DO NOT use gasoline or other types of fuels or flammable solvents to
clean parts, especially in enclosed areas. Fumes from fuels and
solvents can become explosive.
2.3.8
ALWAYS replace the safety devices and guards after repairs and
maintenance.
2.3.9
ALWAYS keep the area around the muffler free of debris such as
leaves, paper, cartons, etc. A hot muffler could ignite the debris and
start a fire.
2.3.10 ALWAYS do Periodic Maintenance as recommended in the Operator’s
Manual.
2.3.11 ALWAYS clean debris from engine cooling fins.
2.3.12 ALWAYS replace worn or damaged components with spare parts
designed and recommended by Wacker Corporation.
2.3.13 ALWAYS disconnect the spark plug on machines equipped with
gasoline engines, before servicing, to avoid accidental start-up.
2.3.14 ALWAYS keep the machine clean and labels legible. Replace all
missing and hard-to-read labels. Labels provide important operating
instructions and warn of dangers and hazards.
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WM 90 Repair
2.4
wc_si000143gb.fm
Safety Information
Label Locations
17
Safety Information
2.5
WM 90 Repair
Safety Labels
Wacker machines use international pictorial labels where needed.
These labels are described below:
Label
Meaning
This molded-in label contains important safety
and operating information. If it becomes illegible, the cover must be replaced. Refer to the
Parts Book for ordering information.
DANGER!
Engines emit carbon monoxide; operate only in
well-ventilated area.
Read the operator's manual for machine information.
DANGER!
No sparks, flames or burning objects near
machine.
Shut off the engine before refueling.
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WM 90 Repair
Label
Safety Information
Meaning
CAUTION!
Use only clean, filtered gasoline fuel.
WARNING!
Hot surface!
WARNING!
Serious injury if struck by compressed spring
or cover. If the spring system cover is removed
improperly, the springs can eject.
Guaranteed sound power level in dB(A).
CAUTION!
Use only clean, filtered gasoline fuel.
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Safety Information
Label
WM 90 Repair
Meaning
A nameplate listing the model number, item
number, revision number, and serial number is
attached to each unit. Please record the information found on this plate so it will be available
should the nameplate become lost or damaged. When ordering parts or requesting service information, you will always be asked to
specify the model number, item number, revision number, and serial number of the unit.
This machine may be covered by one or more
patents.
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20
WM 90 Repair
2.6
Safety Information
Operating Labels
Wacker machines use international pictorial labels where needed.
These labels are described below:
Label
Meaning
Turn the engine switch to the ON position.
Close the choke.
Pull the rewind starter.
Open the choke.
Turn the engine switch to "OFF".
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Safety Information
Label
WM 90 Repair
Meaning
Throttle control lever:
Turtle = Idle or Slow
Rabbit = Full or Fast
Fuel valve:
Closed
Open
Engine stop button:
Press to stop engine.
Choke:
0 = Open
l = Closed
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WM 90
3.
Technical Data
Technical Data
3.1
Specifications
Engine Model
WM 90
Engine
Engine Speed - full
rpm
4200 ± 100
Engine Speed - idle
rpm
2000 ± 100
Clutch Engagement
rpm
2500 ± 100
Spark Plug
type
NGK BM4A or BMR4A
mm (in)
0.6–0.7 (0.023–0.028)
(kg/cm2)
psi
8.0–9.7 (120–140)
Electrode Gap
Cylinder Head
Compression (cold)
Air Cleaner
type
Three-stage with cyclonic precleaner
Engine Lubrication
oil grade
SAE 10W30
SE, SF or higher
Engine Oil Capacity
ml (oz.)
300 (10)
Cooling System
type
Forced air
Ignition system
type
Solid-state, flywheel magneto
Starting system
type
Recoil starter
Governor system
type
Centrifugal flyweight
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Technical Data
3.2
Ref
WM 90
Performance
Description
Ref
Description
a
Maximum torque
d
Recommended horsepower range
b
Continuous rated horsepower
e
Output
c
Maximum horsepower
f
Torque
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WM 90
4.
Theory of Operation
Theory of Operation
4.1
Application
Rammers are designed to compact loose soils and gravel to prevent
settling and to provide a firm, solid base for the placement of footings,
concrete slabs, foundations, and other structures.
4.2
Recommended Fuel
This engine is certified to operate on automotive unleaded gasoline.
Use only fresh, clean gasoline. Gasoline containing water or dirt will
damage fuel system.
4.3
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Before Starting
4.3.1
Read safety instructions at the beginning of this manual.
4.3.2
Make sure that the gas tank is full.
4.3.3
Check engine oil level.
4.3.4
Place rammer on loose soil or gravel. DO NOT start rammer on hard
surfaces such as asphalt or concrete.
25
Theory of Operation
4.4
WM 90
To Start
See Graphic: wc_gr001454
Note: After transporting the rammer horizontally, upright the rammer
and allow the oil to drain back through the engine. It may take up to 2
minutes for the oil level to recover.
4.4.1
Open fuel valve (e).
4.4.2
Turn engine switch to "ON" (d).
4.4.3
If the engine is cold, close choke (b1) on the carburetor.
Note: Occasionally, warm engines will need to be choked.
4.4.4
With throttle in idle position (c2), pull the starter rope (a) until the
engine starts.
4.4.5
On engines equipped with the low oil shutoff switch, see section Low
Oil Shutoff Switch for additional information.
Note: First time use, engines recently serviced, run out of fuel or not
used for long periods of time may need the rope to be pulled more
times to move fuel to the carburetor.
4.4.6
Open choke (b2) on the carburetor as the engine warms up.
Note: A cold engine should be allowed to warm up at the idle position
(c2) for approximately one (1) minute. Failure to open the choke after
the engine attempts to start may cause flooding.
NOTICE: Always open choke (b2) with throttle in idle position (c2).
Opening choke with throttle not in idle position (c2) may result in
rammer motion.
d
c1
a
c2 c3 c4
e
b2
wc_tx000388gb.fm
26
b1
WM 90
Theory of Operation
4.5
To Stop
4.6
4.5.1
Place throttle in the idle position (c2).
4.5.2
Turn engine switch to "OFF" (d).
4.5.3
Close fuel valve (e).
Component Descriptions
Component Illustration
Component Description
The cylinder/crankcase is a single piece aluminum die-casting. The cylinder liner, made of
special cast iron, is molded into the aluminum
casting. The crankcase has a mounting surface on the output shaft side, where the main
bearing cover is attached.
wc_gr001870
The main bearing cover is an aluminum diecasting with thick reinforcing walls and ribs,
which is mounted on the output shaft side of
the crankcase. Remove the main bearing
cover to inspect the inside of the engine. Pilots
and bosses are machined on the cover for
direct mounting of the engine onto rammers.
Oil gauge (a).
a
wc_gr001871
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27
Theory of Operation
WM 90
The crankshaft is forged carbon steel, and the
crank pin is induction-hardened. The output
end of the shaft has a crankshaft gear that is
pressed into position.
wc_gr001872
The connecting rod is an aluminum alloy diecasting and its large and small ends function
as bearings. The piston is an aluminum alloy
casting, and carries two compression rings
and one oil ring.
wc_gr001873
a
The piston rings are made of special cast iron.
The profile of the top ring and the second ring
are shown in the illustration. The oil ring is a
three-part ring designed for better sealing and
less oil consumption.
b
c
wc_gr001874
The camshaft is made of special cast iron, and
camshaft and gear are cast together in one
piece. Both sides of the shaft fit into the plain
bearings on the crankcase and main bearing
cover.
wc_gr001875
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28
WM 90
Theory of Operation
IN
a
The intake valve is located on the flywheel side
of the cylinder head. Hard alloy valve seats are
molded in the cylinder head and satellite is
fused to the exhaust valve face. The cylinder
baffle leads cooling air to the exhaust valve
area for optimum cooling.
Reference: intake (a); exhaust (b).
EX
b
wc_gr001876
The cylinder head is an aluminum die-casting
which utilizes wedge-type combustion chamber for high combustion efficiency.
wc_gr001877
The governor is a centrifugal flyweight type
which ensures constant operation at the
selected speed during load variations. The
governor gear (a) with governor weights is
installed on the main bearing cover.
a
wc_gr001878
wc_tx000388gb.fm
29
Theory of Operation
WM 90
The large fins (a) on the flywheel provide sufficient cooling air capacity for the inlet and
exhaust area and cylinder. The cylinder baffle
directs the cooling air flow efficiently.
a
wc_gr001949
All the rotating and sliding parts are splashlubricated by the oil splasher (a) on the connecting rod.
a
wc_gr001879
The ignition system is a transistor-controlled
magneto system which consists of a flywheel
(a) and an ignition coil (b) with a built-in transistor mounted on the crankcase. This system
has an automatic ignition timing advance system for easy starting.
b
a
wc_gr001880
wc_tx000388gb.fm
30
WM 90
Theory of Operation
WM 90 engines use a diaphragm-type carburetor.
wc_gr001881
The air cleaner is a heavy-duty three-stage
type with cyclonic precleaner.
wc_gr002032
An automatic decompression mechanism (a),
that opens the exhaust valve before the piston
reaches maximum compression, is assembled
on the camshaft for easy starting. During
engine operation the decompression system is
overpowered by centrifugal force and compression is fully utilized to produce power.
a
wc_gr001883
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31
Theory of Operation
4.7
WM 90
Cross Section Across Shaft
1
1
13
2
12
3
11
10
9
8
7
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wc_gr001884
32
WM 90
4.8
Theory of Operation
Cross Section Across Shaft Components
.
Ref
Description
Ref
Description
1
Cylinder head
9
Main bearing cover
2
Piston pin
10
PTO shaft
3
Ignition coil
11
Piston ring
4
Blower housing
12
Piston
5
Recoil starter
13
Muffler
6
Flywheel
14
Exhaust valve
7
Crankcase
15
Intake valve
8
Flange adapter
wc_tx000388gb.fm
33
Theory of Operation
4.9
WM 90
Cross Section Along Shaft
1
14
4
10
g
wc_tx000388gb.fm
34
WM 90
Theory of Operation
4.10 Cross Section Along Shaft Components
.
Ref
Description
Ref
Description
1
Push rod
9
Stiffener
2
Carburetor
10
Plug
3
Air cleaner
11
Oil gauge
4
Tappet
12
Connecting rod
5
Camshaft
13
Spark plug
6
Governor lever
14
Rocker arm
7
Speed control lever
15
Rocker cover
8
Crankshaft
wc_tx000388gb.fm
35
Maintenance
5.
WM 90 Repair
Maintenance
5.1
Periodic Maintenance Schedule
Before
each
use
Every
50
hours
Check for fluid leaks.
Check engine oil.
Check fuel level.
Check for loose hardware.
Clean debris from engine.
Change engine oil*.
Clean air cleaner.
Check and clean spark plug.
Check and adjust valve clearances.
Remove carbon deposits from cylinder
head.
Disassemble and clean carburetor.
Clean fuel filter and fuel tank.
Replace fuel lines.
Overhaul engine.
* Change oil after initial 20 hours of operation on new or rebuilt engines.
wc_tx000392gb.fm
36
Every
100
hours
Every
300
hours
Every
500 hours or
yearly
WM 90 Repair
5.2
Maintenance
Servicing Air Cleaner
NEVER use gasoline or other types of low flash point solvents for
cleaning the air filter. A fire or explosion could result.
WARNING
NOTICE: NEVER run the engine without the main paper air filter (b).
Severe engine damage will occur.
Clean elements using the following procedure:
5.2.1
Remove the air cleaner cover (a). Remove the main paper filter
element (b) and secondary prefilter (c) and inspect them for holes or
tears. Replace the elements if they are damaged.
5.2.2
Main paper filter element (b): Replace the main paper filter element if
it appears heavily soiled.
5.2.3
Prefilter (c): Clean the prefilter with low-pressure compressed air.
When very soiled, wash the prefilter in a solution of mild detergent and
warm water. Rinse it thoroughly in clean water. Allow the prefilter to dry
thoroughly before reinstalling.
Note: Do not oil the prefilter.
5.2.4
Wipe out the filter housing (d) with a clean cloth. Do not use
compressed air.
NOTICE: Do not allow dirt to get into the engine intake port (k) while
cleaning. Damage to engine will result.
5.2.5
Check that the precleaner debris ejector slot (i) is clear.
a
b
c
i
d
k
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37
wc_gr001306
Maintenance
5.3
WM 90 Repair
Servicing Fuel Filter and Fuel Tank
5.3.1
Drain fuel tank completely.
5.3.2
Remove fuel line from fuel flow valve (a).
5.3.3
Unscrew fuel filter assembly (b) from tank.
5.3.4
Clean filter with parts cleaning solvent.
5.3.5
Inspect gasket (c) and filter for damage and replace them if necessary.
5.3.6
Clean sediment from inside of fuel tank.
5.3.7
Re-install gasket, fuel filter, valve, and fuel lines.
c
b
a
wc_gr002017
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38
WM 90 Repair
5.4
wc_tx000392gb.fm
Maintenance
Long-Term Storage
5.4.1
Drain the fuel from the tank.
5.4.2
Start the engine and run it until remaining fuel is used.
5.4.3
Remove the spark plug. Pour approximately 30 ml (1 oz.) of clean SAE
10W30 engine oil into the cylinder through the spark plug opening.
5.4.4
Pull the starter rope slowly to distribute oil in the engine.
5.4.5
Re-install the spark plug.
39
6.
WM 90 Repair
6.1
Tools
Because all possible problems encountered while repairing the
machine cannot be anticipated, it is up to the mechanic to use common
sense and good judgement in tool selection.
The use of any special tools is recommended only for those operations
where the use of conventional tools proves inadequate.
Before substituting another tool or procedure, you should be satisfied
that neither personal injury nor damage to the component will result.
6.2
Ordering Parts
The repair procedures contained in this manual do not include part
numbers. For parts replacement information, refer to the Parts Book
originally supplied with the machine.
If the original Parts Book has been lost, a replacement may be ordered
from Wacker Corporation. When ordering a replacement Parts Book,
please list the model number, item number, revision level, and serial
number of the machine. Parts Books are also available on the Wacker
Corporation Web site. See www.wackergroup.com. Enter the site as a
visitor.
6.3
Reference Numbers ( )
Repair procedures contain reference numbers enclosed in
parentheses ( ). These numbers refer to the item numbers shown on
the assembly drawings and other detailed drawings. They are included
to aid the mechanic in identifying parts and assembling components.
6.4
Weight Block
The weight block symbol gives an approximate weight measurement
to aid the mechanic when lifting/hoisting larger components.
250 kg
(550 lbs.)
wc_gr000843
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40
WM 90 Repair
7.
7.1
Removing Engine from Rammer
See Graphic: wc_gr001954, wc_gr003661, wc_gr001956, and wc_gr001957
wc_tx000389gb.fm
7.1.1
Disconnect the spark plug cap (a) from the spark plug.
7.1.2
Disconnect the fuel line (b) from the carburetor and plug the line.
7.1.3
Disconnect the stop switch wire (c).
7.1.4
Disconnect the wiring (k) from the low-oil unit (l) (if equipped).
7.1.5
Remove the M8 x 16 bolt and washer (d) securing the guard to the
engine.
7.1.6
Remove the M8 bolt and washer (e) securing the guard to the rammer
crankcase.
7.1.7
Remove the six M8 bolts (f) securing the lower guard to the engine and
remove the guard.
7.1.8
Remove the wire running from the engine to the low-oil unit (if
equipped).
7.1.9
Loosen the retainer (g) from the throttle cable. Pry open the clamp (h)
and remove the throttle cable.
7.1.10
Loosen the clamp (i) securing the air intake hose to the carburetor and
remove the hose.
7.1.11
Remove the four nuts (j) securing the engine to the adapter and
remove the heat shield and the engine.
41
WM 90 Repair
d
c
a
k
b
f
j
e
l
wc_gr003661
wc_gr001954
wc_tx000389gb.fm
42
WM 90 Repair
7.2
Draining Oil
Note: In the interests of environmental protection, place plastic
sheeting and a container under the machine to collect the liquid which
drains off. Dispose of this liquid properly.
7.2.1
Remove the drain plug (a) and gasket (b).
7.2.2
Remove oil gauge (c) and gasket (d).
7.2.3
Drain oil from crankcase. Replace plug, oil gauge, and gaskets when
complete.
c
d
a
b
wc_gr001886
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43
7.3
WM 90 Repair
Removing Recoil Starter and Blower Housing
7.3.1
Remove the bolts (a) and remove the recoil starter (b) from the
housing.
7.3.2
Remove the flange bolts (f), cap screw (g), and remove the blower
housing (h).
g
a
b
f
h
wc_gr003650
wc_tx000389gb.fm
44
WM 90 Repair
7.4
Removing Muffler
wc_tx000389gb.fm
7.4.1
Remove the flange nuts (a).
7.4.2
Remove the flange bolts (b).
7.4.3
Remove the bolts and washers (c) and remove the muffler (d) and the
gasket (e).
45
7.5
WM 90 Repair
Removing Governor Lever, Carburetor, Speed Control Lever
wc_tx000389gb.fm
7.5.1
Mark the hole in which the governor spring (a) is attached and remove
the spring.
7.5.2
Loosen the M6 bolt (b) and remove the governor lever (c).
7.5.3
Remove the governor rod (d) and the rod spring (e), and if necessary,
bushing (f).
7.5.4
Remove the carburetor flange (g), the gaskets (h), the carburetor (i).
7.5.5
Remove the bolts (j) securing the insulator (k) and remove the
insulator and gasket (m).
7.5.6
Remove the M6 pivot bolt (n) and washer (o) and remove the speed
control lever (p).
7.5.7
Also remove return spring (q) and spacer (r).
7.5.8
Remove the two M6 x 8 flange bolts (s) and remove the base plate (t).
46
WM 90 Repair
7.6
Removing Ignition Coil, Flywheel, and Spark Plug
7.6.1
Remove the spark plug (a).
7.6.2
Remove the two M6 x 25 bolts (b) and remove the ignition coil (c).
7.6.3
Remove the M12 nut and washer (d), four M6 bolts (e), and remove
the starter pulley (f) and flywheel (g). If necessary, break the nut loose
by tapping the handle of the wrench with a hammer. To remove the
flywheel, hold an aluminum bar (h) against the flywheel side of the
crankshaft and tap the bar with a hammer.
7.6.4
Remove the Woodruff key (i) from the crankshaft.
h
c
a
e
f
b
g
d
i
wc_gr001891
wc_tx000389gb.fm
47
7.7
WM 90 Repair
Removing Rocker Cover and Cylinder Head
wc_tx000389gb.fm
7.7.1
Remove the four M6 x 60 bolts (a) and remove the rocker cover (b) and
gasket (c).
7.7.2
Remove the breather (d), gaskets (e), and spacer (f).
7.7.3
Remove the two M8 x 55 bolts (g) and the two M8 bolts (h), remove
the cylinder head (k) and gasket (l)
7.7.4
Remove the pipes (m) and push rods (n).
7.7.5
If necessary, remove the seal (i) and the guide (j).
48
WM 90 Repair
7.8
Removing Bearing Cover
7.8.1
Remove the nine M6 x 30 bolts and washers (a) and remove the main
bearing cover (b).
Note: If necessary, use a rubber mallet (c) and tap the cover to loosen
it from the crankcase.
c
b
a
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wc_gr001893
49
7.9
WM 90 Repair
Removing Camshaft and Tappets
7.9.1
Lay crankcase on the flywheel side and push the tappets (a) into the
crankcase and remove the camshaft (b).
a
b
b
wc_gr001894
wc_tx000389gb.fm
50
WM 90 Repair
7.10 Removing Connecting Rod and Piston
7.10.1
Remove connecting rod bolts (a) and connecting rod cap (b).
7.10.2
Turn crankshaft until piston (c) comes to top dead center, push out
connecting rod (d) and piston assembly through top of cylinder.
Note: Scrape off all carbon deposits that might interfere with removal
of piston from upper end of cylinder.
7.10.3
Remove the clips (e) and the piston pin (f) to remove connecting rod
from piston.
7.10.4
Being careful not to damage the rings or piston, remove the rings (g)
from the piston by spreading them at the gap and pulling them from the
piston.
e
g
c
f
e
d
b
a
wc_gr001895
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51
WM 90 Repair
7.11 Removing Crankshaft
7.11.1 To remove the crankshaft (a), tap lightly on flywheel end of the
crankshaft with a rubber mallet (b).
a
b
wc_gr001896
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52
WM 90 Repair
7.12 Removing Intake and Exhaust Valves
Note: The procedure is the same for removing each valve.
7.12.1
Remove pivot bolt (a), rocker arm (b), and nut (c).
7.12.1
Press down the spring retainer (d), take out the collet (e), and then
remove spring retainer and valve spring (f).
7.12.2
Remove intake (g) and exhaust (h) valves from cylinder head.
Reference: guide plate (i).
a
b
d
e
c
f
i
g
h
wc_gr001897
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53
8.
WM 90 Repair
8.1
Notes on Reassembly
Observe the following prior to/during reassembly of the engine:
8.2
•
Clean each part carefully, taking special care with the piston, cylinder,
crankshaft, connecting rod, and bearings.
•
Scrape off any carbon deposits on the cylinder head and the piston
head. Be particularly careful when removing carbon from the piston
ring grooves.
•
Inspect oil seals for any damage to the lip. Replace them if damaged.
Apply oil to lip before re-assembling.
•
Replace all gaskets with new ones.
•
Replace keys, pins, bolts and nuts with new ones if necessary.
•
Tighten nuts and bolts to the specified torque settings.
•
During re-assembly, apply oil to all moving parts.
•
Check clearances and end plays. Adjust the clearances as necessary.
•
When mounting any major moving part, rotate it with your hand to
check for any jamming or abnormal noise.
Crankshaft
8.2.1
Wrap the keyway portion of the crankshaft (a) with polyvinyl tape (b)
and insert the crankshaft into the crankcase, taking care not to damage
the oil seal lip.
a
b
wc_gr001898
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54
WM 90 Repair
8.3
Reassembling Piston
See Graphic: wc_gr001874, wc_gr001899 and wc_gr001900
Install each piston ring in the correct groove of the piston by widening
it enough to slide it over the piston.
Note: When installing the piston rings, make sure not to twist the rings
too much as they may become damaged.
8.3.1
Install the three-piece oil ring (c) first. When installing the oil ring, install
the middle section first, then the outer two outer sections.
8.3.2
Install the second ring (b). When installing the second ring, make sure
that the “RN” mark is face up.
8.3.3
Install the top ring (a).
a
b
c
wc_gr001874
wc_gr001900
wc_gr001899
wc_tx000389gb.fm
55
8.4
WM 90 Repair
Reassembling Piston and Connecting Rod
8.4.1
Install the piston (a) onto the connecting rod (b) using the piston pin (c)
and two clips (d).
d
a
c
d
b
wc_gr001901
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56
WM 90 Repair
8.5
Installing Piston
See Graphic: wc_001902, wc_gr001903, and wc_gr001904
8.5.1
Position the piston rings so that the gaps in the rings are at 90°
intervals from each other (a = top ring, b = second ring, c = oil ring).
8.5.2
Apply oil to the piston rings, the cylinder bore, and the large end of the
connecting rod.
8.5.3
Position the “MA” mark on the crankshaft so that it faces the flywheel
side of the engine when assembled. Then, using a ring guide (d), hold
the piston rings in and lower the piston into the cylinder.
Note: If you do not have a ring guide, hold the piston rings in with your
fingers while tapping lightly on the piston head with a block of wood or
rubber mallet.
8.5.4
Rotate the crankshaft down to the bottom dead center and lightly tap
the piston head until the large end of the connecting rod touches the
crank pin.
8.5.5
To mount the connecting rod, line up the matching marks (e) and fit the
connecting rod cap to the connecting rod. Secure the two halves
together using two M5 bolts. Torque bolts to: 5.9–7.8 Nm (4.3–5.7
ft.lbs).
8.5.6
Check for free movement of the connecting rod by turning the
crankshaft slowly.
d
"MA"
wc_gr001902
e
wc_gr001904
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57
8.6
WM 90 Repair
Installing Tappets and Camshaft
8.6.1
Oil the tappets (a) and install them. Push them in fully to avoid damage
during camshaft (b) installation.
8.6.2
Remove spacer (c) to allow viewing of timing mark.
8.6.3
Lubricate the bearing surfaces of camshaft. Align the timing marks (d)
on the camshaft with the timing marks on the crankshaft and install the
camshaft into the crankcase.
NOTICE: Incorrect valve timing will cause malfunction of the engine.
a
c
d
b
wc_gr001905
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58
WM 90 Repair
8.7
Adjusting Crankshaft End Play
Adjust the end play to 0.2 mm (0.008 in.) using the proper spacer.
Determine the proper spacer in the following manner:
8.7.1
Measure the height “A”. Distance from main bearing cover mating
surface (a) to the inner race of the ball bearing (b).
8.7.2
Measure the depth “B”. Distance from the crankcase mating surface
(c) to the crankshaft gear (d).
B-A = side clearance
Side clearance - 0.2 mm (0.008 in.) = thickness of crankshaft shim.
Spacer shims are available in the following thicknesses:
0.6 mm (0.024 in.)
0.8 mm (0.031 in.)
1.0 mm (0.039 in.)
8.7.3
Reference: crankcase (e); crankshaft (f); depth gauge (g).
g
b
f
d
d
a
c
e
wc_gr001906
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59
8.8
WM 90 Repair
Installing Main Bearing Cover
8.8.1
Lubricate the oil seal and bearing surfaces with engine oil.
8.8.2
Coat the mating surfaces of the main bearing cover (a) and crankcase
(b) with Loctite® 515 Gasket Eliminator or equivalent.
8.8.3
Using nine M6 x 30 bolts and washers (c) secure the main bearing
cover to the crankcase. Tighten bolts in pattern shown on illustration.
Torque the bolts to: 9.8–11.8 Nm (7.2–8.7 ft.lbs.).
4
3
5
6
2
7
1
b
9
8
a
c
wc_gr001907
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60
WM 90 Repair
8.9
Cylinder Head
8.9.1
Clean carbon and gum deposits from the valves, seats, ports, and
guides. Inspect them once clean. Replace valves that are badly
burned, pitted, or warped.
8.9.2
When installing valves in cylinder head, oil the valve stems and insert
them into valve guide. Then place cylinder head on a flat table, install
spring and spring retainer.
8.9.3
Valve guides should be replaced when valve stem clearance exceeds
specifications. See Clearance Data and Limits Table.
8.9.4
Draw valve guides out and press new guides in. See Clearance Data
and Limits Table.
8.9.5
After replacing valves and guides, lap valves in place until a uniform
ring shows around the face of the valve. Clean valves and wash
cylinder head thoroughly.
8.9.6
Install cylinder head onto cylinder with new head gasket. Tighten the
four M8 x 55 flange bolts in a crisscross pattern, in three incremental
steps using the following torque values:
Step 1: 5.0 Nm (3.6 ft.lbs.)
Step 2: 9.8 Nm (7.2 ft.lbs.)
Step 3: 18.6–20.6 Nm (13.7–15.2 ft.lbs.)
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61
WM 90 Repair
8.10 Reassembling Rocker Arms and Push Rods
8.10.1 Insert push rods (a) into crankcase. Place push rod tip into the hollow
of the tappet top.
NOTICE: An oil return slot is located next to the tappet boss. If you do
not put the push rod in the tappet properly, the push rods will fall into
the crankcase. If this happens, removal of the main bearing cover will
be necessary to remove them.
8.10.2 Place the gasket (b) on the crankcase. Position the intake valve (c)
and the exhaust valve (d) into the cylinder head (e). Using four M8 x
55 flange bolts (f), secure the cylinder head to the crankcase .
8.10.3 Position the guide plate (g). Insert the valve spring (h), the spring
retainer (i), and secure them to the valve using the collet (j). Complete
for both intake and exhaust.
8.10.4 Using the pivot bolt (l) and the M6 nut (m), install the rocker arm (k).
Complete for both intake and exhaust.
l
k
j
m
i
h
g
f
e
d
c
b
a
wc_gr001908
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WM 90 Repair
8.11 Adjusting Valve Clearances
See Graphic: wc_gr001909 and wc_gr001910
Note: Check and adjust valve clearances when engine is cold.
8.11.1
Temporarily fit the flywheel in position.
8.11.2
Position the piston at the top dead center of the compression stroke by
matching the alignment mark on the flywheel (a) with the alignment
mark on the crankcase (b).
8.11.3
Loosen the nut (c) under the rocker arm. Position a feeler gauge (e)
as shown and turn the pivot bolt (d) until the clearance measures 0.07–
0.13 mm (0.0028–0.0051 in.). Tighten pivot bolt. Complete for both
intake and exhaust valves.
8.11.4
Check operation of the valves by turning the crankshaft. Recheck the
valve clearances.
b
a
wc_gr001909
e
d
c
wc_gr001910
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8.12 Installing Rocker Cover and Spark Plug
Note: Replace the gasket with a new one each time the rocker cover
is removed.
8.12.1 Using four M6 bolts (a), secure the rocker cover (b) and gasket (c) to
the cylinder head.
8.12.2 Remove any carbon deposits from the spark plug and inspect the
electrode for damage. Replace the spark plug if necessary. Use NGK
BM6A or BMR6A
Electrode gap: 0.6–0.7 mm (0.23–0.27 in.).
Spark Plug Torque:
New plug: 11.8–14.7 Nm (8.7–10.9 ft.lbs.)
Reused plug: 22.6–24.5 Nm (16.6–18.1 ft.lbs.)
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WM 90 Repair
8.13 Installing Flywheel Magneto
8.13.1
Place the Woodruff key in the keyway of the crankshaft. Thoroughly
wipe off oil and grease from the tapered portion of the crankshaft and
also from the flywheel center hole.
8.13.2
Install the flywheel, M12 nut and washer to the crankshaft. Hold the
flywheel using a strap wrench and torque the nut to 44.2–49.1 Nm
(32.5–36.2 ft.lbs.).
8.14 Installing Ignition Coil
8.14.1
Using two M6 x 25 bolts and washers, mount the ignition coil (a) to the
engine. Before tightening the bolts, adjust the air gap using a thickness
gauge (b). Adjust the air gap to 0.3–0.5 mm (0.012–0.020 in.).
a
b
wc_gr001913
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WM 90 Repair
8.15 Installing Governor, Speed Control System, and Carburetor
8.15.1 Install governor lever (a) to governor shaft, then tighten the locking bolt
(b) temporarily.
8.15.2 Install baseplate (t) to crankcase using two M6 x 8 flange bolts (s).
8.15.3 Install the speed control lever (p), friction washer (o), pivot bolt (n),
spacer (r) and return spring (q).
8.15.4 Attach the governor spring (c) to proper holes (as marked during
disassembly) of governor lever and speed control lever.
8.15.5 Using bolts (j), install insulator (k) and gasket (m).
8.15.6 Install carburetor (i) and gaskets (h) to cylinder head. Also install
appropriate carburetor flange (g).
8.15.7 Install bushing (f). Install governor rod (d) to governor lever and throttle
lever of carburetor. Attach spring (e) over governor rod.
8.15.8 See section Adjusting Governor System.
s
r
p
o
n
q
t
m
i
e
k
f
d
a
c
j
h
g
wc_gr001890
b
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WM 90 Repair
8.16 Adjusting Governor System
8.16.1
Turn the speed control lever (a) all the way toward the high speed
position and secure it by tightening the self-locking screw.
8.16.2
Check that the governor lever (b) is pulled by the governor spring (c)
and carburetor throttle valve is fully open.
8.16.3
Turn the governor shaft (d) clockwise all the way using a screw driver,
and tighten the lock bolt to secure the lever on the shaft.
8.16.4
Loosen the lock nut to allow the speed control lever to move freely.
Reference: governor rod spring (e); normal hooking position of
governor spring (f).
e
c
f
b
a
d
wc_gr001914
8.17 Installing Muffler
8.17.1
wc_tx000389gb.fm
Using two flange nuts (a), two flange bolts (b), and bolts and washers
(c), install muffler (d) and gasket (e).
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WM 90 Repair
8.18 Installing Blower Housing and Recoil Starter
8.18.1 Install the blower housing (h) using the flange bolts (f) and cap screw
(g).
8.18.2 Install the recoil starter (b) to the housing using the bolts (a).
g
a
b
f
h
wc_gr003650
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8.19 Re-installing Engine
See Graphic: wc_gr001954, wc_gr003661, wc_gr001956, and wc_gr001957
wc_tx000389gb.fm
8.19.1
Position the engine so that mounting studs protrude from the adapter
plate mounted to the rammer crankcase. Position heatshield and
secure engine and heatshield to rammer with four nuts (j).
8.19.2
Connect the wire from the low-oil unit (l) (if equipped) to the engine.
8.19.3
Using six M8 bolts (f) mount the guards to the engine. Secure upper
guard to engine using M8 x 16 bolt (d) and to rammer crankcase using
M8 bolt (e).
8.19.4
Secure the throttle cable to the engine by crimping clamp (h). Feed
cable through retainer (g) and tighten screw.
8.19.5
Secure air intake hose to engine by crimping clamp (i).
8.19.6
Reconnect stop switch wire (c).
8.19.7
Connect the wiring (k) from the low-oil unit (l) (if equipped).
8.19.8
Reconnect fuel line (b) to the carburetor.
8.19.9
Reconnect spark plug (a).
69
WM 90 Repair
d
c
a
k
b
f
j
e
l
wc_gr003661
wc_gr001954
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8.20 Break-in Operation
A new engine or one that has been completely overhauled by being
fitted with a new piston, rings, valves, and connecting rod should be
thoroughly run-in before being put into service.
Good bearing surfaces and running clearances between the various
parts can only be established by operating the engine under reduced
speed and loads for a short period of time.
Run-in the engine according to the schedule below. During the run-in
period, check for oil leaks, make final carburetor adjustments, and
regulate the engine operating speed.
Step
Engine Load
Speed (rpm)
Duration (min.)
1
No load
2500
10
2
No load
3000
10
3
No load
3600
10
4
0.7 kW (1.0 hp)
3000
30
5
1.0 kW (1.9 hp)
3600
60
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Sub Systems
9.
WM 90 Repair
Sub Systems
9.1
Magneto
The ignition system of the WM 90 is a breakerless flywheel magneto
with an automatic advancing system.
This system has no breaker points and thus is free from the starting
and running problems associated with dirty, burnt, or corroded breaker
points.
The electronic automatic advancing ensures easy starts and high
performance at operating speed by advancing the ignition timing to the
most suitable point.
9.2
Engine Basic Electric Theory
9.2.1
Revolution of the flywheel generates electricity in the primary side of
the ignition coil, and the base current I1 flows to the power transistor.
Current I1 turns the power transmitter “ON” and the electric current I2
flows.
9.2.2
At lower engine revolution, when the flywheel reaches the ignition
point, the low speed ignition timing control circuit operates to run the
base current I3 to turn the signal transistor A “ON” allowing the current
I1 to bypass as current I4.
At this moment, the power transistor turns “OFF” and the current I2 is
abruptly shut off resulting in the high voltage generated in the
secondary coil which produces sparks at the spark plug.
9.2.3
At higher engine revolution, the advancing control circuit operates at
the ignition timing to run the base current I5 to turn the signal transistor
B “ON” allowing the current I1 to bypass as current I6.
At this moment the power transistor turns “OFF” and the current I2 is
abruptly shut off resulting in the high voltage generated in the
secondary coil which produces sparks at the spark plug.
The operating timing of the advancing control circuit advances in
accordance with the increase of engine speed resulting in the
advancing of the ignition timing shown in the chart.
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WM 90 Repair
9.3
Sub Systems
Electrical Components
Ref
Description
Ref
Description
1
Low-speed ignition timing circuit
9
Spark plug
2
Signal transistor A
10
Ignition timing (BTDC)
3
Automatic advancing control circuit
11
Engine revolution (rpm)
4
Signal transistor B
12
Step advancing
5
Resistor
13
Stop switch
6
Power transistor
14
Connector
7
Primary coil
15
Ignition coil
8
Secondary coil
16
Flywheel
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Sub Systems
9.4
WM 90 Repair
Automatic Decompression System
WM 90 engines employ an automatic decompression system as a
standard feature. This system enables easy starting of the engine, with
lighter recoil pull. The automatic decompression system releases the
compression of the engine by lifting up the exhaust valve at cranking
speeds.
At the end of the compression process, the release lever (a) lifts up the
tappet (b) which in turn opens the exhaust valve slightly to release
compression. The release lever has a flyweight (c) on one end and a
crescent cam (d) on the other. When the engine is cranked, the
crescent cam projects above the cam profile and lifts up the tappet
because the gravity force on the weight is larger than the centrifugal
force on the weight.
Reference: exhaust cam (e); camshaft (f); rotation direction (g).
b
a
c
d
e
e
g
f
wc_gr001917
When the cranking speed reaches a specified rpm, the crescent cam
(d) is retracted under the cam profile because the centrifugal force
applied to the flyweight (c) becomes larger than the force of the gravity
on the weight and thus it is shifted to the position shown.
c
b
a
d
e
e
g
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f
74
wc_gr001918
WM 90 Repair
9.5
Sub Systems
Diaphragm-Type Carburetor
Ref
Description
Comment
1
Engine impulse
The alternating action of the positive pressure and negative pressure inside the engine crankcase operates the
fuel pump diaphragm.
2
Fuel pump diaphragm The fuel pump diaphragm undulates in response to the
engine impulse and as a result, it feeds the fuel through
the fuel pump.
3
Fuel inlet
The fuel inlet is the opening through which fuel is drawn
from the fuel tank.
4
Inlet valve
The inlet valve opens when the diaphragm is submitted
to the action of a negative pressure in response to the
movement of the pump diaphragm and the inlet valve
shuts when it is submitted to a positive pressure.
5
Outlet valve
The outlet valve shuts when it is submitted to the action
of a negative pressure and opens when submitted to a
positive pressure.
6
Inlet screen
The inlet screen filters the fuel that is drawn from the
fuel tank to the carburetor.
7
Inlet needle valve
The inlet needle valve controls the fuel that is fed from
the fuel pump to the metering chamber.
8
Throttle valve
The throttle valve controls the volume of air drawn into
the engine, thereby changing the engine speed.
9
Air vent hole
The air vent hole is open to the atmosphere, with the
purpose of allowing smooth operation of the metering
diaphragm.
10
Metering diaphragm
The metering diaphragm has the function of operating
the metering lever, which is pulled up by the variations in
the negative pressure of the engine.
11
Metering lever
The metering lever has the function of opening/closing
the inlet valve by transmitting the movements of the
metering diaphragm to that valve.
12
Metering lever spring
The metering lever spring has the function of pushing up
the metering lever, thereby shutting the needle valve
when the engine is stopped and when the metering
chamber is full of fuel.
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75
Sub Systems
WM 90 Repair
Ref
Description
Comment
13
Metering chamber
The metering chamber is the fuel storage compartment
that has the function of supplying fuel to the nozzle
holes and other parts.
14
First idle hole
The first idle hole is the only fuel supply hole that is
available when the engine is idling.
15
Second and third idle
holes
The second and third idle holes have the function of
supplying fuel when the throttle is at an intermediate
opening state between the idling state and the fully open
state.
16
Idle needle
The idle needle has the function of controlling the fuel
when the engine is at idling speeds and when the throttle is at low speed position.
17
High-speed needle
The high speed needle has the function of controlling
the fuel when the engine is operating at high speed and
when the throttle is at a high speed position.
18
Main nozzle
The main nozzle is the hole through which fuel is
ejected when the engine is operating at high speed and
when the throttle is at a high speed position.
19
Venturi
The venturi has the function of increasing the air flow ar
the nozzle section, thereby improving the atomization of
the fuel.
20
Choke valve
The choke valve has the function of shutting the suction
of air when the engine is started at a cold state, thereby
securing the temporary supply of rich fuel/air mixture.
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WM 90 Repair
Sub Systems
2
4
5
6
3
1
8
19
15
18
14
17
20
16
7
11
13
10
9
wc_gr001919
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77
12
Sub Systems
9.6
WM 90 Repair
Carburetor Disassembly Procedure
Prior to disassembling the carburetor, wash it with an appropriate
cleaning solvent.
9.6.1
Loosen the pump cover screw (14) and remove the screw and the
pump cover (13).
9.6.2
Remove the pump gasket (12) and the diaphragm (11).
9.6.3
Place the carburetor with the metering side up and remove the
metering cover screws (8).
9.6.4
Remove the metering cover (7), the diaphragm assembly (6), and the
gasket (5).
9.6.5
Loosen the metering lever pin screw (17) and remove the lever (4), pin
(18), spring (3), and needle valve (2).
14
13
12
15
20
11
1
10
9
19
16
2
18
17
3
4
5
6
7
8
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wc_gr001920
78
WM 90 Repair
9.7
Sub Systems
Carburetor Inspection
9.8
9.7.1
Clean the carburetor and components with an appropriate solvent.
9.7.2
Check the gaskets for any deformation and/or damage. Replace any
deformed or damaged gaskets.
9.7.3
Make sure that the pump diaphragm (11) is not damaged. Also make
sure that the inlet valve and outlet valve are flat and not bent.
9.7.4
Make sure that the metering diaphragm (6) is not damaged and that
the plate is not bent.
9.7.5
Check the throttle shaft (19) and the choke shaft (20) for smooth
operation.
9.7.6
Check the inlet screen (1) for dirt. If the screen is dirty, wash it and blow
it out with compressed air.
9.7.7
Check the inlet valve for abnormal wearing. If the inlet valve is worn,
replace it.
Carburetor Reassembly
wc_tx000390gb.fm
9.8.1
Mount the inlet screen (1) to the carburetor body.
9.8.2
Mount the inlet needle (2), metering lever spring (3), metering lever (4),
and other related components.
9.8.3
Mount, in this order, the metering gasket (5), metering diaphragm, (6),
and cover (7). Tighten the four cover screws.
9.8.4
Next, mount in this order, the pump diaphragm (11), pump gasket (12),
and pump cover (13). Tighten the pump cover screw.
79
Sub Systems
9.9
WM 90 Repair
Carburetor Adjustments
Idling Adjustment:
9.9.1
Start the engine and adjust the idle adjust screw (15) so that the engine
is running at a speed slightly lower than the speed at which the clutch
engages.
High-Speed Adjustment:
9.9.2
Set the throttle valve (16) to the fully open position and check whether
the engine rotates at the maximum engine speed as listed in the
Technical Data section.
14
13
12
15
20
11
1
10
9
19
16
3
4
2
18
17
5
6
7
8
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WM 90 Repair
Recoil Starter
10. Recoil Starter
10.1 Recoil Starter Disassembly
For machines with item numbers 0009386 rev. 111 and lower;
0009340 rev. 111 and lower; 0620051 rev. 107 and lower
Wear eye protection when working on the recoil starter.
CAUTION
To release the reel spring power:
10.1.1
Hold the starter knob and pull out the starter rope.
10.1.2
Pull out the rope fully and align the rope knot in the reel with the rope
guide.
10.1.3
Hold the reel down firmly with both thumbs, taking care to not allow it
to spring back.
Note: The following procedure requires the help of an assistant.
10.1.4
Remove the knot from the reel, untie the knot and pull the rope out
toward the starter knob.
10.1.5
While controlling the reel with your thumbs, slowly wind it back as far
as it will go.
Note: When the rope is pulled out to its full length, the force stored in
the spring reaches its maximum. Take care when handling the reel.
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Recoil Starter
WM 90 Repair
To remove the components:
10.1.6 Grip the case (a) and loosen the set screw (b).
10.1.7 Remove, in this order: the set screw, the ratchet guide (c), the friction
spring (d), and the ratchet (e).
Remove the reel:
10.1.8 Hold down the reel (f) gently, to keep it from escaping from its case,
and rotate it slowly back and forth by quarter turns until it moves
smoothly.
10.1.9 Lift the reel up slightly and remove it from the case.
10.1.10 If the spring is about to pop out of the reel, repeat the previous two
steps.
Note: Since the spring is stored in the reel, make sure not to drop or
shake the reel after removing it. Place it on a flat secure surface such
as a table.
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WM 90 Repair
Recoil Starter
Reassembly
Re-installing the reel:
10.1.11 Apply grease (Exxon Unirex or equivalent) (a) to the surface of the
case.
10.1.12 Adjust the position of the inner end of the spring reel. Reference (b):
position where the inner end of the spring touches the rib of the
bearing.
10.1.13 Hold the reel in such a way that the inner end of the spring hooks onto
the shaft hook (c) and then place the reel carefully back into the case.
See Graphic wc_gr001833 and wc_gr001834
Reinstalling the components:
10.1.14 Mount the ratchet into the reel. The ratchet should be in the closed
position (a).
10.1.15 Mount the ratchet guide assembly (b), taking care to not move the
ratchet or lose the friction spring (d).
10.1.16 Tighten the set screw (c). Torque to 5.5 Nm (4.0 ft.lbs.).
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Recoil Starter
WM 90 Repair
Tensioning the reel spring:
10.1.17 Grip the case and turn the reel 6 times counterclockwise.
10.1.18 Rotate the reel so that the rope hole (a) is aligned with the rope guide
(b).
Installing the rope:
Note: This procedure requires help from an assistant.
10.1.19 Pass the rope through the rope guide and the rope hole of the reel and
pull through approximately 20 cm (7-3/4 in.) out of the reel.
10.1.20 Tie a knot in the end of the rope.
10.1.21 Put the rope into the reel, taking care that the rope end does not stick
up.
10.1.22 Grasp the rope firmly with one hand approximately 50 cm (19-5/8 in.)
from the rope guide and keep the rope tense, taking care that the rope
is not pulled into the reel.
10.1.23 Release the reel carefully and allow the rope to be wound back slowly
by the force of the spring until the knob reaches the rope guide.
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WM 90 Repair
Recoil Starter
10.2 Checking the Recoil Starter After Reassembly
For machines with item numbers 0009386 rev. 111 and lower;
0009340 rev. 111 and lower; 0620051 rev. 107 and lower
Note: Carry out the following procedures to ensure proper operation of
the starter assembly.
10.2.1
•
If the starter knob is too heavy to pull, check that each part has been
assembled as specified.
•
If the ratchet does not work, check for missing parts such as the friction spring.
10.2.2
wc_tx000627gb.fm
Pull the starter rope 2–3 times.
Pull out the starter knob as far as it will go.
•
If the starter rope remains in the rope slot in the reel, the spring may
be over-stressed. To fix this, pull out the starter rope approximately 30
cm (11-3/4"), and controlling the rotation of the reel with your thumb,
allow the starter rope to rewind about one or two turns.
•
If the starter rope rewinds slowly or only partially, apply grease or oil
to the rotary parts or the friction surfaces. If this does not help, try
winding up the spring one or two turns, taking care to not over-stress
the spring.
•
If there is a sound indicating that the spring is off the hook and the
starter rope cannot be wound back, reassemble the recoil starter from
the beginning.
85
Recoil Starter
WM 90 Repair
10.3 Starter Assembly Exploded View
For machines with item numbers 0009386 rev. 112 and higher;
0009340 rev. 112 and higher; 0620051 rev. 108 and higher
1
4
5
6
13
9
7
10
8
3
11
2
12
wc_gr002880
Ref
Description
Ref
Description
1
Starter assembly
8
Spring
2
Rope
9
Ratchet wheel
3
Handle
10
Cover
4
Wear plate
11
Lock washer
5
Return spring
12
Locknut
6
Starter pulley
13
Starter housing
7
Washer
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86
--
WM 90 Repair
Recoil Starter
10.4 Disassembling the Starter
10.4.1
Remove the starter assembly from the fan cover and release the
spring tension as described in section Replacing the Starter Rope.
10.4.2
Untie the rope (2) and remove the handle (3).
10.4.3
Remove the locknut (12), lock washer (11), and cover (10).
10.4.4
Remove the ratchet (9), spring (8), and washer (7). Note the position
of the ratchet and the spring to ensure proper reassembly.
10.4.5
Slowly lift the rope reel pulley (6) from the starter housing (13). Also
remove the wear plate (4). If necessary, carefully remove the spring (5)
from the rope reel pulley.
10.5 Inspecting the Starter
Starter Return Spring
Replace the starter return spring if it is broken, or appears distorted or
twisted. Check that the starter return spring ends are bent 180° (a). The
starter return spring may be difficult to seat in the slots on the starter
housing and the rope reel pulley, if the return spring ends are stretched
out (b) or damaged.
Rope Reel Pulley
Inspect the rope reel pulley for wear in the area where the starter return
spring makes contact. Remove any dirt and grease from between the
spring windings. Slip the rope reel pulley over the center post in the
housing and check its movement. The rope reel pulley should rotate
freely on the post with a minimum amount of side play.
Ratchet
Check the ratchet tooth for wear. The tip (c) should be pointed, not
rounded. A worn ratchet may slip when engaging the flywheel.
Replace the ratchet when it is worn.
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Recoil Starter
WM 90 Repair
Rope
Check the rope length. It is 150 cm (60 in.) when new. If the rope is too
short, it may bottom out when pulled and damage the starter.
b
a
d
e
c
f
wc_gr002881
10.6 Assembling the Starter
10.6.1 Clean all the components of the starter before reassembling the
starter.
10.6.2 Note: To reduce dirt and dust from collecting between the spring
windings, avoid using grease to lubricate the tarter return spring or the
inside of the reel where the spring seats. Use a light lubricating oil such
as WD40 instead.
10.6.3 Install the spring (e)(5) by placing the outside end of the spring in the
slot (d) on the rope reel pulley (f) (6). Wrap the spring in a
counterclockwise direction inside the pulley until it is completely
wound. Oil the spring lightly once it is wound.
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WM 90 Repair
Recoil Starter
10.6.4
Lightly grease the center post of the housing and install the wear plate
(4) and the rope reel pulley. Rotate the rope reel pulley until the spring
seats in the slot at the center of the housing (13). Install the washer (7)
over the center post and seat it into the rope reel pulley.
NOTICE: Failure to replace the washer will cause the ratchet to bind
and prevent the rope reel pulley from rotating freely.
10.6.5
Add the spring (8) and the ratchet (9) to the assembly. Do not grease
the ratchet.
10.6.6
Install the cover (10) and secure it in place using the lock washer (11)
and locknut (12). Torque the locknut to 8 Nm (6 ft.lbs.). Install the rope
as described in section Starter Rope Replacement.
10.7 Replacing the Starter Rope
The starter rope can be replaced without removing the rope reel pulley
from the starter assembly.
Removal:
10.7.1
Remove the starter assembly from the flywheel housing.
10.7.2
Lift the rope through the notch (a) in the drum. Pull out as much of the
rope as possible. Hold the rope and let the spring pull the drum around
clockwise until all spring tension is released.
10.7.3
Untie the knot and remove the rope.
Installation:
wc_tx000627gb.fm
10.7.4
Thread the new rope through the rope reel pulley and then through the
housing. Install the handle and knot (b) each end of the rope as shown.
Be sure the end of the rope does not protrude from the rope reel (c) or
it may interfere with the movement of the starter.
10.7.5
Lift the rope up through the notch in the edge of the drum and rotate
the drum counterclockwise to wind the spring. Guide (d) the rope
around as the drum is rotated. After two complete revolutions, remove
the rope from the notch and allow it to be pulled around the drum by
the spring tension (e). Repeat this procedure until all the rope is on the
drum and the handle rests against the housing.
10.7.6
Reattach the starter assembly to the flywheel housing.
89
Recoil Starter
WM 90 Repair
a
b
c
d
e
wc_gr002882
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WM 90 Repair
Clearance Data and Limits Table
11. Clearance Data and Limits Table
11.1 Term Descriptions
The following table lists critical dimensions of specific parts. The
“Standard” column lists the dimension of the part as new from the
factory. The “Limit” column lists the maximum allowance. If the
measurement exceeds the “Limit” dimension listed, replace or repair
the part.
Item
Standard
mm (in.)
Limit
mm (in.)
0.05 or less
(0.002)
0.1
(0.004)
0.8–1.1
(0.0315–0.0433)
2.0
(0.079)
5.500–5.518
(0.2165–0.2172)
---
Cylinder head
Flatness
wc_gr001921
Intake/exhaust valve contact width
wc_gr001922
Intake exhaust
wc_gr001923
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91
Item
Piston
STD
Outer diameter at skirt in thrust
direction
WM 90 Repair
Standard
mm (in.)
Limit
mm (in.)
50.97–50.99
50.88
(2.0031)
(2.0067–2.0075)
Oversize
(+0.25)
(2.0165–2.0173)
Oversize
(+0.50)
(2.0264–2.0272)
51.38
(2.0228
0.035–0.080
(0.0014–0.0031)
0.15
(0.006)
2nd
0.035–0.080
(0.0014–0.0031)
0.15
(0.006)
Oil Ring
0.010–0.065
(0.0004–0.0026)
0.15
(0.006)
10.991–11.009
(0.4327–0.4334)
11.035
(0.4344)
10.992–11.000
(0.4328–0.4331)
6.05
(0.238)
51.22–51.24
51.47–51.49
51.13
(2.0123)
wc_gr001925
Ring groove-side clearance
Top
wc_gr001926
Piston pin hole
wc_gr001927
Piston pin outside diameter
wc_gr001928
wc_tx000391gb.fm
92
WM 90 Repair
Item
Standard
mm (in.)
Limit
mm (in.)
0.010–0.049
(0.0004–0.0019)
0.25
(0.010)
Top ring
0.15–0.35
(0.006–0.014
1.5
(0.0591)
2nd ring
0.35–0.55
(0.014–0.022
1.5
(0.0591)
Oil ring
0.05–0.25
(0.002–0.010
1.5
(0.0591)
Clearance between piston and cylinder at skirt
wc_gr001929
Piston ring end gap
wc_gr001930
Cylinder
Inner diameter Standard
51.000–51.019
STD
wc_gr001924
(2.008–2.009)
First reboring
51.250–51.269
(2.0177–2.0185)
Same as above
Second
reboring
51.500–51.519
(2.0276–2.0283)
Same as above
Roundness after reboring
Less than 0.01
(0.0004)
Cylindricity after reboring
Less than 0.01
(0.0004)
wc_tx000391gb.fm
To be rebored
when the difference between
max. and min.
diameter
reaches 0.1
(0.004).
93
Item
WM 90 Repair
Standard
mm (in.)
Limit
mm (in.)
20.000–20.013
20.1
(0.7913)
Connectng rod
Large-end inner diameter
(0.7874–0.7879)
120˚
Clearance between large end and crank pin
0.037–0.063
(0.0015–0.0025)
0.2
(0.008)
wc_gr001933
Small end inner diameter
11.010–11.021
(0.4335–0.4339)
11.08
(0.4362)
wc_gr001934
Clearance bewteen small end and piston pin
0.010–0.029
(0.0004–0.0011)
wc_gr001935
wc_tx000391gb.fm
94
0.12
(0.0047)
WM 90 Repair
Item
Standard
mm (in.)
Limit
mm (in.)
0.1–0.7
1.0
(0.04)
Large end side clearance
(0.004–0.028)
wc_gr001936
Crankshaft
Crank pin outer diameter
19.950–19.963
(0.7854–0.7859)
19.85
(0.7815)
wc_gr001937
Journal outer diameter
D1
D2
D1 and D2
19.988–19.997
(0.7869–0.7873)
---
wc_gr001938
Camshaft
Cam peak height
(intake and exhaust)
18.3–18.5
(0.720–0.728)
wc_gr001939
wc_tx000391gb.fm
95
18.15
(0.715)
Item
Journal outside diameter
D1
WM 90 Repair
Standard
mm (in.)
Limit
mm (in.)
9.972–9.987
9.95
(0.3917)
D1
(0.3926–0.3932)
D2
(0.3926–0.3932)
D2
9.972–9.987
9.95
(0.3917)
wc_gr001940
Intake/exhaust valves
5.440–5.455
Intake
(0.2142–0.2148)
5.35
(0.2106)
Valve stem outer diameter
Exhaust
5.426–5.444
(0.2136–0.2143)
5.35
(0.2106)
wc_gr001941
Clearance between valve stem
and valve guide
0.045–0.078
Intake
(0.0018–0.0031)
Exhaust
0.056–0.092
(0.0022–0.0036)
0.3
(0.0118)
0.3
(0.012)
wc_gr001942
Valve clearance in cold state
Intake/
Exhaust
wc_gr001943
wc_tx000391gb.fm
96
0.07–0.13
(0.0028 - 0.0051)
---
WM 90 Repair
Item
Standard
mm (in.)
Limit
mm (in.)
7.960–7.975
(0.3134–0.3140)
---
8.00–8.015
(0.3150–0.3140)
---
0.025–0.055
(0.0010–0.0022)
---
Tappet
Stem outside diameter
wc_gr001944
Guide inside diameter
wc_gr001945
Tappet guide clearance
wc_gr001946
Valve seat angle
(intake and exhaust)
Valve cutter angle (a)
Valve contact width (b)
a: 90°
b: 0.8 – 1.1
(0.031–0.043)
b b
a
wc_gr001948
wc_tx000391gb.fm
97
2.0
(0.079)
Item
WM 90 Repair
Standard
mm (in.)
Limit
mm (in.)
26.7
(1.05)
---
Valve spring free length
wc_gr001947
wc_tx000391gb.fm
98
WM 90 Repair
Troubleshooting
12. Troubleshooting
12.1 Troubleshooting Introduction
If the engine shows any sign of malfunction, the cause should be
determined immediately and the appropriate countermeasures should
be taken to prevent the problem from worsening. This troubleshooting
section describes certain known problems, their possible causes, and
appropriate action to take. Note, however, that the list of problems
listed here is not all-encompassing. Generally speaking, since there is
the possibility of multiple causes for a single problem, please use your
experience and common sense when deciding on what action to take.
The following three conditions must be met for the engine to start:
1. The cylinder must be filled with the proper fuel-air mixture.
2. There must be good compression in the cylinder.
3. There must be good spark, properly timed to ignite the mixture.
The engine cannot be started unless the these three conditions are
met. There are other factors as well that will make engine starting
difficult, such as a heavy load on the engine when attempting to start,
or heavy back pressure due to a long exhaust pipe.
12.2 Troubleshooting Procedures
12.2.1
Fuel System Problems:
12.2.1.1 No gasoline in tank, or the fuel cock is closed.
12.2.1.2 The carburetor is not choked sufficiently especially when engine is
cold.
12.2.1.3 Water, dust or gum in the gasoline interfering with fuel flow to
carburetor.
12.2.1.4 Inferior grade gasoline or poor quality gasoline not vaporized enough
to produce the correct fuel-air mixture.
12.2.1.5 The carburetor needle valve is held open by dirt or gum. This trouble
can be detected as the fuel flows out of the carburetor when the engine
is idling.
12.2.1.6 If the carburetor overflows, excessive fuel runs into the cylinder when
starting the engine, making the fuel-air mixture too rich to burn. If this
happens, remove the spark plug and turn the starting pulley a few turns
to let the rich fuel-air mixture out of the spark plug hole and into the
atmosphere. Keep the choke valve open during this operation. Dry the
spark plug well, screw it into place, and try to start the engine again.
wc_tx000393gb.fm
99
Troubleshooting
WM 90 Repair
12.2.2 Ignition System Problems:
Check the following when experiencing a lack of spark.
12.2.2.1 Wires of the ignition coil, spark plug, or contact breaker disconnected.
12.2.2.2 Ignition coil damaged or shorted.
12.2.2.3 Spark plug wire wet or soaked with oil.
12.2.2.4 Spark plug dirty or wet.
12.2.2.5 Spark plug gap incorrect.
12.2.2.6 Spark plug electrode connected or bridged.
12.2.2.7 Incorrect spark timing.
12.2.2.8 Proper connection of all wires.
12.2.3 Compression System:
If starting difficulties and loss of power are not due to the fuel system
or ignition system, the fault may be due to lack of compression. Make
the following checks to the compression system.
12.2.3.1 Internal engine is completely dry because of a long period of storage.
12.2.3.2 Loose or broken spark plug. This causes a hissing noise made by the
fuel-air mixture running out of the cylinder in compression stroke
during cranking.
12.2.3.3 Damaged head gasket or loose cylinder head. This will also make a
hissing noise.
12.2.3.4 If the correct compression is not obtained even after remedying the
above, problems may be due to incorrect valve clearance.
Disassemble the engine and proceed further as follows:
•
Valve stuck open due to carbon or gum on the valve stem.
•
If the piston rings are stuck on the piston, remove the piston and connecting rod from the engine. Clean and replace the parts if necessary.
12.2.4 Engine Misfires:
12.2.4.1 Incorrect spark plug electrode gap. Adjust gap.
12.2.4.2 Ignition cable worn.
12.2.4.3 Weak spark.
12.2.4.4 Ignition wire connections loose.
12.2.4.5 Water in gasoline.
12.2.4.6 Insufficient compression.
wc_tx000393gb.fm
100
WM 90 Repair
12.2.5
Troubleshooting
Engine Stops:
12.2.5.1 Fuel tank empty. Water, dirt, gum, etc. in gasoline.
12.2.5.2 Vapor lock. Gasoline evaporating in the fuel lines due to overheating
of the engine.
12.2.5.3 Vapor lock in the fuel lines or carburetor due to using too volatile gas
blend (winter formula) in the hot season.
12.2.5.4 Air vent hole in the fuel tank cap plugged.
12.2.5.5 Bearing parts seized due to lack of lubrication.
12.2.5.6 Magneto or ignition coil faulty.
12.2.6
Engine Overheats:
12.2.6.1 Crankcase oil level low. Add oil immediately.
12.2.6.2 Spark timing incorrect.
12.2.6.3 Low-grade gasoline being used or engine is overloaded.
12.2.6.4 Cooling air circulation restricted.
12.2.6.5 Cooling air path misdirected causing loss of cooling efficiency.
12.2.6.6 Cylinder head cooling fins clogged with dirt.
12.2.6.7 Engine being operated in an enclosed space without sufficient cooling
air.
12.2.6.8 Exhaust gas discharge restricted, or carbon deposits in the
combustion chamber.
12.2.6.9 Engine running on low-octane gasoline detonates due to heavy load at
low speed.
12.2.7
Engine Knocks:
12.2.7.1 Poor quality gasoline.
12.2.7.2 Engine operating under heavy load at low speed.
12.2.7.3 Carbon or lead deposits in the cylinder head.
12.2.7.4 Spark timing incorrect.
12.2.7.5 Loose connecting rod bearing due to wear.
12.2.7.6 Loose piston pin due to wear.
12.2.8
Engine Backfires Through Carburetor:
12.2.8.1 Water or dirt in gasoline, or low grade gasoline.
12.2.8.2 Intake valve stuck.
12.2.8.3 Valves overheated or hot carbon particles in the combustion chamber.
12.2.8.4 Engine cold.
wc_tx000393gb.fm
101
Troubleshooting
WM 90 Repair
Notes
wc_tx000393gb.fm
102
Threadlockers and Sealants
Threadlocking adhesives and sealants are specified throughout this
manual by a notation of “S” plus a number (S#) and should be used
where indicated. Threadlocking compounds normally break down at
temperatures above 175°C (350°F). If a screw or bolt is hard to
remove, heat it using a small propane torch to break down the sealant.
When applying sealants, follow instructions on container. The sealants
listed are recommended for use on Wacker equipment.
TYPE
( ) = Europe
Loctite 222
Hernon 420
Omnifit 1150 (50M)
COLOR USAGE
Purple Low strength, for locking threads smaller
than 6 mm (1/4”).
Hand tool removable.
Temp. range: -54 to 149°C (-65 to 300°F)
Blue
Medium strength, for locking threads
Loctite 243
Hernon 423
larger than 6 mm (1/4”).
Omnifit 1350 (100M)
Hand tool removable.
Loctite 271/277
Red
High strength, for all threads up to 25 mm
Hernon 427
(1”).
Omnifit 1550 (220M)
Heat parts before disassembly.
Loctite 290
Green Medium to high strength, for locking
Hernon 431
preassembled threads and for sealing
Omnifit 1710 (230LL)
weld porosity (wicking).
Gaps up to 0.13 mm (0.005”)
Loctite 609
Green Medium strength retaining compound for
Hernon 822
slip or press fit of shafts, bearings, gears,
Omnifit 1730 (230L)
pulleys, etc.
Gaps up to 0.13 mm (0.005”)
Loctite 545
Brown Hydraulic sealant
Hernon 947
Omnifit 1150 (50M)
Loctite 592
White
Pipe sealant with Teflon for moderate
Hernon 920
pressures.
Omnifit 790
Loctite 515
Purple Form-in-place gasket for flexible joints.
Hernon 910
Fills gaps up to 1.3 mm (0.05”)
Omnifit 10
PART NO. –
SIZE
73287 - 10 ml
29311 - .5 ml
17380 - 50 ml
29312 - .5 ml
26685 - 10 ml
73285 - 50 ml
28824 - .5 ml
25316 - 10 ml
29314 - .5 ml
79356 - 50 ml
26695 - 6 ml
73289 - 50 ml
70735 - 50 ml
Threadlockers and Sealants (continued)
Threadlocking adhesives and sealants are specified throughout this
manual by a notation of “S” plus a number (S#) and should be used
where indicated. Threadlocking compounds normally break down at
temperatures above 175°C (350°F). If a screw or bolt is hard to
remove, heat it using a small propane torch to break down the sealant.
When applying sealants, follow instructions on container. The sealants
listed are recommended for use on Wacker equipment.
TYPE
( ) = Europe
COLOR USAGE
Loctite 496
Clear
Instant adhesive for bonding rubber, metal
Hernon 110
and plastics; general purpose.
Omnifit Sicomet 7000
For gaps up to 0.15 mm (0.006”)
Read caution instructions before using.
Loctite Primer T
Aerosol Fast curing primer for threadlocking,
Hernon Primer 10
Spray
retaining and sealing compounds. Must
Omnifit VC Activator
be used with stainless steel hardware.
Recommended for use with gasket
sealants.
PART NO. –
SIZE
52676 - 1oz.
2006124-6 oz.
Torque Values
Torque Values
Metric Fasteners (DIN)
TORQUE VALUES (Based on Bolt Size and Hardness)
8.8
10.9
WRENCH SIZE
12.9
Size
Nm
ft.lb.
Nm
ft.lb.
Nm
ft.lb.
Metric
Inch
Metric
Inch
M3
1.2
*11
1.6
*14
2.1
*19
5.5
7/32
2.5
–
M4
2.9
*26
4.1
*36
4.9
*43
7
9/32
3
–
M5
6.0
*53
8.5
6
10
7
8
5/16
4
–
M6
10
7
14
10
17
13
10
–
5
–
M8
25
18
35
26
41
30
13
1/2
6
–
M10
49
36
69
51
83
61
17
11/16
8
–
M12
86
63
120
88
145
107
19
3/4
10
–
M14
135
99
190
140
230
169
22
7/8
12
–
M16
210
155
295
217
355
262
24
15/16
14
–
M18
290
214
405
298
485
357
27
1-1/16
14
–
M20
410
302
580
427
690
508
30
1-1/4
17
–
1 ft.lb. = 1.357 Nm
* = in.lb.
1 inch = 25.4 mm
Torque Values
Torque Values (continued)
Inch Fasteners (SAE)
Size
Nm
ft.lb.
Nm
ft.lb.
Nm
ft.lb.
Metric
Inch
Metric
Inch
No.4
0.7
*6
1.0
*14
1.4
*12
5.5
1/4
–
3/32
No.6
1.4
*12
1.9
*17
2.4
*21
8
5/16
–
7/64
No.8
2.5
*22
3.5
*31
4.7
*42
9
11/32
–
9/64
No.10
3.6
*32
5.1
*45
6.8
*60
–
3/8
–
5/32
1/4
8.1
6
12
9
16
12
–
7/16
–
3/32
5/16
18
13
26
19
33
24
13
1/2
–
1/4
3/8
31
23
45
33
58
43
–
9/16
–
5/16
7/16
50
37
71
52
94
69
16
5/8
–
3/8
1/2
77
57
109
80
142
105
19
3/4
–
3/8
9/16
111
82
156
115
214
158
–
13/16
–
–
5/8
152
112
216
159
265
195
24
15/16
–
1/2
3/4
271
200
383
282
479
353
–
1-1/8
–
5/8
1 ft.lb. = 1.357 Nm
* = in.lb.
1 inch = 25.4 mm
Wacker Construction Equipment AG
·
Preußenstraße 41
· D-80809 München
· Tel.: +49-(0)89-3 54 02 - 0 · Fax: +49 - (0)89-3 54 02-3 90
Wacker Corporation · P.O. Box 9007 · Menomonee Falls, WI 53052-9007 · Tel. : (262) 255-0500 · Fax: (262) 255-0550 · Tel. : (800) 770-0957
Wacker Asia Pacific Operations · Skyline Tower, Suite 2303, 23/F · 39 Wang Kwong Road, Kowloon Bay, Hong Kong · Tel. +852 2406 60 32 · Fax: +852 2406 60 21

Engine - Wacker Neuson

Transcription

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