Kawasaki KZ-ZX-GPZ-500-550 1979-1985 Service Manual
KZ500/550 & 2x550 1979-1985
SERVICE REPAIR MAINTENANCE
Chapter One
General Information
Chapter Two
Troubleshooting
Chapter Three
Periodic Maintenance, Lubrication and Tune-up
Chapter Four
Engine
Chapter Five
Clutch
Chapter Six
Transmission
Chapter Seven
Fuel and Exhaust
Chapter Eight
Electrical Systems
Chapter Nine
Wheels, Tires and Brakes
Chapter Ten
1982
and Later Service lnformation
Wiring Diagrams
Chassis
Supplement
Index
CONTENTS
QUICK REFERENCE DATA
CHAPTER ONE
GENERAL INFORMATION
Manual organization
Service hints
Safety first
Expendable supplies
CHAPTER TWO
TROUBLESHOOTING
Starting difficulties
Poor performance
Clutch and transmission
Drive train
Chassis
Brakes
CHAPTERTHREE
LUBRICATION, MAINTENANCE AND TUNE-UP
Battery
Engine oil and filter
General lubrication
Clutch adjustment
Drive chain
Swing arm
Steering
Front forks
Rear shock absorbers
Tires
Wheel bearing lubrication
Disc brake
Drum brake
Engine tune-up
...............................................................................................
.....................................................................................................
.............................................................................................................
XI
1
Shop tools
Emergency tool kits
Troubleshooting and tune-up
equipment
9
Electrical system
Charging system
Lighting
Fuses
Wiring
.................................................................
Air filter
Nuts, bolts and fasteners
Fuel system
Spark plugs
Air suction valves (U.S. models)
Valve clearance
Contact breaker points
Ignition timing
(Contact point ignition)
Ignition timing
(Transistorized ignition)
Carburetor
Cylinder compression
Storage
33
CHAPTER FOUR
ENGINE 70
Tools
Engine design
Break-in
Servicing engine in frame
Cam chain and tensioner
Valve cover
Camshaft
Cylinder head
CHAPTER FIVE
CLUTCH
CHAPTER SIX
TRANSMlSSlON
.................................................................................................................................
Oil cooler
Removal/installation
Oil filter bypass valve
Oil pump
Crankcase
Secondary shaft and starter clutch
Crankshaft and connecting rods
Cam chain inspection
Valves and guides
Cylinder block
Pistons and rings
............................................................................................................................
Operation
Clutch release mechanism
....................
Sprocket cover
Neutral switch
Engine sprocket
Shift linkage
..
.......................................................................................
Primary chain inspection
Crankcase assembly
124
Clutch
133
Shift detent
Transmission
Shift drum and forks
Transmission gears
CHAPTERSEVEN
FUEL AND EXHAUST SYSTEMS
Carburetor operation
Carburetor troubleshooting
Rejetting
Carburetor tuning
Carburetor service
Fuel level inspection
Idle mixture adjustment
(Non-U.S. models)
CHAPTER EIGHT
ELECTRICAL
Wiring diagrams
Fuses
Battery
Ignition system
Contact breaker points and
condenser service
Spark plugs
Ignition advance mechanism
Ignition coil
Pickup coils
(Transistorized ignition)
SYSTEM
......................................................................................................
...................................................................................
Fast idle adjustment
Crankcase breather
Air suction system
(U.S. models)
Fuel tank
Fuel tap
Fuel level sending unit
Exhaust system
Alternator stator
Alternator rotor
Starting system
Starter motor
Starter clutch
Starter solenoid
Lighting system
Turn signal cancelling system
Fuel level sensor
Fuel gauge
Horn
148
169
CHAPTER NINE
WHEELS, TIRES AND BRAKES
Wheels
Front wheel
Speedometer gear lubrication
Rear wheel
Wheel bearings and seals
Tubeless tires
Brakes
Hydraulic disc brakes
Brake system bleeding
CHAPTERTEN
CHASSIS
Fairing
Front forks
Steering head
SUPPLEMENT
1982 AND LATER SERVICE INFORMATION
............................................................................................................................
...................
.............
Brake fluid change
Brake line replacement
Disc brake pad replacement
Disc brake calipers
Master cylinder rebuilding
Front master cylinder
Rear master cylinder
Brake discs
Drum brake
Rear shock
Swing arm
Drive chain
...........................................
..............................................................
192
228
246
INDEX
WIRING DIAGRAMS
......................................................................................................................
...................
..
.............................................................
End Of
307
Book
TIRES AND TIRE PRESSURE
ModellTire size Pressure
0.215 Ib.
(0.97.5
kg)
CYLINDER HEAD
TORQUE
SEQUENCE
@
load
Over 215 Ib.
(Over 97.5
kg)
KZ500-01, 02, KZ550-A1 (tube-type)
Front-3.25H-19 4PR
Rear-3.75-18 4PR
KZ500-03, KZ550-A2,B2,Dl (tubeless)
Front-3.25H-19 4PR
Rear-3.75H-18 4PR
KZ550-C1, C2 (tubeless)
Front-3.25s-19 4PR 25 psi (175 kPa) 25 psi (175 kPa)
Rear-130/90-16 67H PR
KZ550-HI (tubeless)
Front-3.25H-19 4PR
Rear-4.00-18 4PR
KZ550-F1, Ml (tubeless)
Front-100190-19 57s
Rear-130190.16 67s
ZX550-A1, A2 (tubeless)
Front-100190-18 56H
Rear-120180-18 62H
TUNE.UP SPECIFICATIONS
1979-1981; 1982-on US.
1982-on non-US.
Valve clearance (cold)
28 psi (200 kPa) 28 psi (200 kPa)
36 psi (245 kPa)
28 psi (200 kPa) 28 psi (200 kPa)
32 psi (225 kPa)
21 psi (150 kPa)
25 psi (175 kpa)
21 psi (147 kPa)
28 psi (196 kPa) 28 psi (196 kPa)
32 psi (225 kPa)
0.024-0.028 in. (0.6-0.7 mm)
NGK D8EA; ND X24ES-U
NGK D8ES; ND X24ESR-0
0.004-0.008 in. (0.10-0.20 mm)
0.006-0.010 in. (0.15-0.25 mm)
40 psi (280 kPa)
40 psi (280 kPa)
28 psi (200 kPa)
See tire data decal
25 psi (175 kPa)
28 psi (196 kPa)
36 psi (245 kPa)
1,150-1,250 rpm
All other models 1,000-1,100 rpm
X
FASTENERTORQUES
ft..lb.
mkf4
Alternator rotor bolt
Camshaft cap bolts
Clutch hub nut
Connecting rod cap nuts
Crankcase bolts
Small
Large
Cylinder base nuts
Cylinder head
Bolts
Nuts
Engine mounting bolts
KZ550-HI, F1, MI
All others
Engine mounting bracket
bolts
Engine sprocket plate
bolts
Oil drain plug
Except KZ550-F1, MI
KZ550-F1, -M1
Oil filter mounting bolt
Secondary shaft nut
Spark plugs 10 1.4
Chassis
Front axle nut
KZ550-F1, MI 47 6.5
All others 58 8.0
Front axle pinch bolt 14.5 2.0
Front fork clamp bolts
KZ550-F1, MI
Upper
Lower
All other models
15 2.1
20 2.8
13 1.8
Rear axle nut
KZ550-F1, M1
2x550-At, A2
All others
54 7.5
69 9.5
60 8.0
Steering stem head bolt
KZ550bH1, F1, M1 31 4.3
All other models 35 4.5
Swing arm pivot shaft
KZ550-H1
KZ550-F1, M1
ZX550-A1, A2
58 8.0
9.5 1.3
65 90
LUBRICANTS AND FUEL
Engine oil
SAE 10W-40, 1OW-50, 20W-40, 20W-50, rated SE or higher
Front fork oil SAE 5W20
Fuel
87 pump octane (RON
~t
MON)/2
91 research octane (RON)
Final drive gear oil
Model Standard
API GL-5 Hypoid gear oil; SAE 80 or SAE 90
FORK AIR PRESSURE*
Range
KZ550-C 8.5 psi (60 kPa) 7-10 psi (50-70 kPa)
KZ550
F1, MI 7.5 psi (59 kPa) 7-10 psi (49-69 kPa)
1
8.5-1
1
psi (60-80 kPa)
psi (60-80 kPa)
H1 10.0 psi (70 kPa) 8.5-1
All others
10 psi (70 kPa)
Never exceed 36 psi (245 k Pa) air pressure as it will damage the oil seals.
REAR SHOCK AIR PRESSURE*
Model Standard Range
KZ550
F1 11 psi (78 kPa) 11-10 psi (78-147 kPa)
Never exceed 71 psi (490 kPa) air pressure as it will damage the oil seals.
STANDARD FORK OIL* (1982-on)
Model Dry capacity Wet capacity Oil level
fl.
U.S.
fl.
oz. (cc)
U.S.
ox. (CC) in.
KZ550-HI 7.9 t 0.1 7.2 19.8
(mm)
+O.l
(234 k2.5) (215) (503 12)
KZ550-F1, MI 11.05 k0.15 9.4 16.3 +0.1
ZX550-A1, A2 7.7 k0.08
(327 +4) (280) (416 +2)
(229 22.5) 472
*.
18.58
tO.l
(
k
2)
Fork oil level is checked with forks fully extended and the fork spring removed. Use oil grade SAE 5W-20.
'
Not specified.
XI1
This detailed, comprehensive manual covers
Kawasaki
text gives complete information on maintenance,
repair and overhaul. Hundreds of photos and
drawings guide you through every step. The book
includes all you need to know to keep your bike
running right.
Chapters One through Ten contain general
information on all models and specific information on
1979-1 98 1 models. The Supplement at the end of the
book contains information on 1982 and later models
that differ from earlier years. Where repairs are
practical for the owner/mechanic, complete
procedures are given. Equally important, difficult jobs
are pointed out. Such operations are usually more
economically performed by a dealer or independent
garage.
A shop manual is a reference. You want to be able
to find information fast. As in all Clymer books, this
one is designed with this in mind. All chapters are
thumb tabbed. Important items are indexed at the
end of the book. All the most frequently used
specifications and capacities are summarized on the
Quick Reference
Keep the book handy. It will help you to better
understand your Kawasaki, lower repair and
maintenance costs and generally improve your
satisfaction with your bike.
KZ500/550
and
ZX550
pages at the beginning of the book.
models. The expert
CHAPTER
ONE
GENERAL INFORMATION
The troubleshooting, maintenance, tune-up,
and step-by-step repair procedures in this book
are written specifically for the owner and home
mechanic. The text is accompanied by helpful
photos and diagrams to make the job as clear
and correct as possible.
Troubleshooting, maintenance, tune-up, and
repair are not difficult if you know what to do
and what tools and equipment to use. Anyone
of average intelligence, with some mechanical
ability, and not afraid to get their hands dirty
can perform most of the procedures in this
book.
In some cases, a repair job may require tools
or skills not reasonably expected of the home
mechanic. These procedures are noted in each
it
chapter and
is recommended that you take
the job to your dealer, a competent mechanic,
or a machine shop.
MANUAL
ORGANIZATION
This chapter provides general information,
safety and service hints. Also included are lists
of recommended shop and emergency tools as
well as a brief description of troubleshooting
and tune-up equipment.
Chapter Two provides methods and sugges-
tions for quick and accurate diagnosis and
repair of problems. Troubleshooting pro-
cedures discuss typical symptoms and logical
methods to pinpoint the trouble.
Chapter Three explains all periodic lubrica-
tion and routine maintenance necessary to keep
your motorcycle running well. Chapter Three
also includes recommended tune-up pro-
cedures, eliminating the need to constantly con-
sult chapters on the various subassemblies.
Subsequent chapters cover specific systems
such as the engine, transmission, and electrical
system. Each of these chapters provides
disassembly, inspection, repair, and assembly
procedures in a simple step-by-step format. If a
it
repair is impractical for the home mechanic
is
indicated. In these cases it is usually faster and
less expensive to have the repairs made by a
dealer or competent repair shop. Essential
specifications are included in the appropriate
chapters.
When special tools are required to perform a
task included in this manual, the tools are
lustrated.
It
may be possible to borrow or rent
il-
these tools. The inventive mechanic may also be
able to find a suitable substitute in his tool box,
or to fabricate one.
NOTE,
The terms
CAUTION,
specific meanings in this manual. A
vides additional or explanatory information.
and
WARNING
NOTE
have
pro-
A
2
CHAPTER
ONE
CAUTION
is used to emphasize areas where
equipment damage could result if proper
precautions are not taken. A
WARNING
is used to
stress those areas where personal injury or
death could result from negligence, in addition
to possible mechanical damage.
SERVICE
HINTS
Time, effort, and frustration will be saved
and possible injury will be prevented if you
observe the following practices.
Most of the service procedures covered are
straightforward and can be performed by
anyone reasonably handy with tools. It is sug-
gested, however, that you consider your own
capabilities carefully before attempting any
operation involving major disassembly of the
engine.
Some operations, for example, require the
use of a press. It would be wiser to have these
performed by a shop equipped for such work,
rather than to try to do the job yourself with
makeshift equipment. Other procedures require
precision measurements. Unless you have the
skills and equipment required, it would be bet-
ter to have a qualified repair shop make the
measurements for you.
Repairs go much faster and easier if the parts
that will be worked on are clean before you
begin. There are special cleaners for washing
the engine and related parts. Brush or spray on
the cleaning solution, let stand, then rinse it
away with a garden hose. Clean all oily or
greasy parts with cleaning solvent as you
remove them.
WARNING
Never use gasoline as a cleaning agent.
It presents an extreme fire hazard. Be
sure to work in a well-ventilated area
when using cleaning solvent. Keep a fire
extinguisher, rated for gasoline fires,
handy in any case.
Much of the labor charge for repairs made by
dealers is for the removal and disassembly of
other parts to reach the defective unit. It is fre-
quently possible to perform the preliminary
operations yourself and then take the defective
unit in to the dealer for repair, at considerable
savings.
Once you have decided to tackle the job
yourself, make sure you locate the appropriate
section in this manual, and read it entirely.
Study the illustrations and text until you have a
good idea of what is involved in completing the
job satisfactorily. If special tools are required,
make arrangements to get them before you
start. Also, purchase any known defective parts
prior to starting on the procedure. It is
frustrating and time-consuming to get partially
into a job and then be unable to complete it.
Simple wiring checks can be easily made at
home, but knowledge of electronics is almost a
necessity for performing tests with complicated
electronic testing gear.
During disassembly of parts keep a few
general cautions in mind. Force is rarely needed
to get things apart. If parts are a tight fit, like a
bearing in a case, there is usually a tool de-
signed to separate them. Never use a
screwdriver to pry apart parts with machined
surfaces such as cylinder head or crankcase
halves. You will mar the surfaces and end up
with leaks.
Make diagrams wherever similar-appearing
parts are found. You may think you can
-
remember where everything came from
but
mistakes are costly. There is also the possibility
you may get sidetracked and not return to work
-
for days or even weeks
in which interval,
carefully laid out parts may have become
disturbed.
Tag all similar internal parts for location,
and mark all mating parts for position. Record
number and thickness of any shims as they are
removed. Small parts such as bolts can be iden-
tified by placing them in plastic sandwich bags
that are sealed and labeled with masking tape.
Wiring should be tagged with masking tape
and marked as each wire is removed. Again, do
not rely on memory alone.
Disconnect battery ground cable before
working near electrical connections and before
disconnecting wires. Never run the engine with
the battery disconnected; the alternator could
be seriously damaged.
Protect finished surfaces from physical
damage or corrosion. Keep gasoline and brake
fluid off painted surfaces.
GENERAL
INFORMATION
3
Frozen or very tight bolts and screws can
often be loosened by soaking with penetrating
oil like Liquid Wrench or
striking the bolt head a few times with a ham-
mer and punch (or screwdriver for screws).
Avoid heat unless absolutely necessary, since it
may melt, warp, or remove the temper from
many parts.
Avoid flames or sparks when working near a
charging battery or flammable liquids, such as
gasoline.
No parts, except those assembled with a press
fit, require unusual force during assembly. If a
part is hard to remove or install, find out why
before proceeding.
Cover all openings after removing parts to
keep dirt, small tools, etc., from falling in.
When assembling two parts, start all
fasteners, then tighten evenly.
Wiring connections and brake shoes, drums,
pads, and discs and contact surfaces in dry
clutches should be kept clean and free of grease
and oil.
When assembling parts, be sure all shims and
washers are replaced exactly as they came out.
Whenever a rotating part butts against a sta-
tionary part, look for a shim or washer. Use
new gaskets if there is any doubt about the con-
dition of old ones. Generally, you should apply
gasket cement to one mating surface only, so
the parts may be easily disassembled in the
future. A thin coat of oil on gaskets helps them
seal effectively.
Heavy grease can be used to hold small parts
in place if they tend to fall out during assembly.
However, keep grease and oil away from elec-
trical, clutch, and brake components.
High spots may be sanded off a piston with
sandpaper, but emery cloth and oil do a much
more professional job.
Carburetors are best cleaned by disas-
sembling them and soaking the parts in a com-
mercial carburetor cleaner. Never soak gaskets
and rubber parts in these cleaners. Never use
wire to clean out jets and air passages; they are
easily damaged. Use compressed air to blow out
the carburetor, but only if the float has been
removed first.
Take your time and do the job right. Do not
forget that a newly rebuilt engine must be
WD-40,
then sharply
broken in the same as a new one. Refer to your
owner's manual for the proper break-in pro-
cedures.
SAFETY FIRST
Professional mechanics can work for years
and never sustain a serious injury. If you
observe a few rules of common sense and
safety, you can enjoy many safe hours servicing
your motorcycle. You could hurt yourself or
damage the motorcycle if you ignore these
rules.
1.
Never use gasoline as a cleaning solvent.
2.
Never smoke or use a torch in the vicinity of
flammable liquids such as cleaning solvent in
open containers.
3.
Never smoke or use a torch in an area where
batteries are being charged. Highly explosive
hydrogen gas is formed during the charging
process.
4.
Use the proper sized wrenches to avoid
damage to nuts and injury to yourself.
5.
When loosening a tight or stuck nut, be
guided by what would happen if the wrench
should slip. Protect yourself accordingly.
6.
Keep your work area clean and uncluttered.
7.
Wear safety goggles during all operations in-
volving drilling, grinding, or use of a cold
chisel.
8.
Never use worn tools.
9.
Keep a fire extinguisher handy and be sure it
is rated for gasoline (Class
(Class
C)
fires.
EXPENDABLE SUPPLIES
Certain expendable supplies are necessary.
These include grease, oil, gasket cement, wiping
rags, cleaning solvent, and distilled water.
Also, special locking compounds, silicone
lubricants, and engine and carburetor cleaners
may be useful. Cleaning solvent is available at
most service stations and distilled water for the
battery is available at supermarkets.
SHOP TOOLS
For complete servicing and repair you will
need an assortment of ordinary hand tools
(Figure
1).
B)
and electrical
4
CHAPTER
ONE
As a minimum, these include:
Combination wrenches
Sockets
Plastic mallet
Small hammer
Impact driver
Snap ring pliers
Gas pliers
Phillips screwdrivers
Slot (common) screwdrivers
Feeler gauges
Spark plug gauge
Spark plug wrench
Special tools required are shown in the
chapters covering the particular repair in which
they are used.
Engine tune-up and troubleshooting pro-
cedures require other special tools and equip-
ment. These are described in detail in the
following sections.
EMERGENCY TOOL
KITS
Highway
A
small emergency tool kit kept on the bike is
handy for road emergencies which otherwise
could leave you stranded. The tools and spares
Figure
2
listed below and shown in
handle most roadside repairs.
a. Motorcycle tool kit (original equipment)
b. Impact driver
c. Silver waterproof sealing tape (duct tape)
(3
d. Hosedamps
e. Silicone sealer
f. Lock
g. Flashlight
h. Tire patch kit
i. Tire irons
j.
k. Waterless hand cleaner
1.
'N'
Plastic pint bottle (for oil)
Rags for clean up
sizes)
Seal
will let you
Off-Road
A few simple tools and aids carried on the
motorcycle can mean the difference between
walking or riding back to camp or to where
Figure
repairs can be made. See
A
few essential spare parts carried in your
truck or van can prevent a day or weekend of
trail riding from being spoiled. See
3.
Figure
4.
GENERAL
INFORMATION
5
On
the Motorcycle
a. Motorcycle tool kit (original equipment)
b. Drive chain master link
c. Tow line
d. Spark plug
e. Spark plug wrench
f. Shifter lever
g.
Clutch/brake lever
h. Silver waterproof sealing tape (duct tape)
i.
Loctite Lock
In
the Truck
'N'
Seal
a. Control cables (throttle, clutch, brake)
b. Silicone sealer
c. Tire patch kit
d. Tire irons
e. Tire pump
f. Impact driver
g. Oil
WARNlNG
Tools and spares should be carried on
the tnotorcycle
a simple fall could result in serious in-
jury from a sharp tool.
-
not in clothing where
TROUBLESHOOTING AND
TUNE-UP EQUIPMENT
Voltmeter, Ohmmeter,
and
Ammeter
For testing the ignition or electrical system, a
good voltmeter is required. For motorcycle use,
an instrument covering 0-20 volts is satisfac-
tory. One which also has a 0-2 volt scale is
necessary for testing relays, points, or in-
dividual contacts where voltage drops are much
_+
X
smaller. Accuracy should be
volt.
An ohmmeter measures electrical resistance.
This instrument is useful for checking conti-
nuity (open and short circuits), and testing
fuses and lights.
The ammeter measures electrical current.
Ammeters for motorcycle use should cover 0-50
amperes and 0-250 amperes. These are useful
for checking battery charging and starting cur-
rent.
Several inexpensive vakl's (volt-ohm-milli-
ammeter) combine all three instruments into
one which fits easily in any tool box. See
ure
5.
However, the ammeter ranges are usually
Fig-
too small for motorcycle work.
Hydrometer
The hydrometer gives a useful indication of
battery condition and charge by measuring the
6
CHAPTER
ONE
specific gravity of the electrolyte in each cell.
See
Figure
6.
Complete details on use and inter-
pretation of readings are provided in the elec-
trical chapter.
Compression Tester
The compression tester measures the com-
pression pressure built up in each cylinder. The
results, when properly interpreted, can indicate
general cylinder, ring, and valve condition. See
Figure
7.
Extension lines are available for hard-
to-reach cylinders.
Dwell Meter (Contact Breaker
Point Ignition Only)
A
dwell meter measures the distance in
degrees of cam rotation that the breaker points
remain closed while the engine is running. Since
GENERAL INFORMATION
7
this angle is determined by breaker point gap,
dwell angle is an accurate indication of breaker
point gap.
Many tachometers intended for tuning and
testing incorporate a dwell meter as well. See
Figure
8.
Follow the manufacturer's instruc-
tions to measure dwell.
Tachometer
A
tachometer is necessary for tuning. See
Figure
8.
Ignition timing and carburetor ad-
justments must be performed at the specified
idle speed. The best instrument for this purpose
is one with a low range of 0-1,000 or 0-2,000
rpm for setting idle, and a high range of 0-4,000
or more for setting ignition timing at 3,000
rpm. Extended range (0-6,000 or 0-8,000 rpm)
instruments lack accuracy at lower speeds. The
instrument should be capable of detecting
25
changes of
NOTE:
not accurate enough for correct
justmen
Strobe
This instrument is necessary for tuning, as
rpm on the low range.
The motorcycle's tachometer is
I.
Timing Light
idle
ad-
it
permits very accurate ignition timing. The light
flashes at precisely the same instant that No.
1
cylinder fires, at which time the timing marks
on the engine should align. Refer to Chapter
Three for exact location of the timing marks for
your engine.
II
Suitable lights range from inexpensive neon
bulb types ($2-3) to powerful xenon strobe
Figure
9.
lights ($20-40). See
are difficult to see and must be used in dimly
areas. Xenon strobe timing lights can be used
outside in bright sunlight.
Tune-up Kits
Many manufacturers offer kits that combine
several useful instruments. Some come in a con-
venient carry case and are usually less expensive
than purchasing one instrument at a time.
Figure
10
shows one of the kits that is available.
The prices vary with the number of instruments
included in the kit.
Manometer (Carburetor Synchronizer)
A
manometer is essential for accurately syn-
chronizing carburetors on multi-cylinder
engines. The instrument detects intake pressure
differences between carburetors and permits
them to be adjusted equally.
manometer costs about $25 and comes with
detailed instructions for use. See
Neon timing lights
lit
A
suitable
Figure
11.
CHAPTER
ONE
Fire Extinguisher
A
fire extinguisher is a necessity when work-
ing on a vehicle. It should be rated for both
Class
B (flammable liquids - gasoline, oil,
paint, etc.) and
etc.) type fires.
reach. See
It
Figure
Class
C
(electrical - wiring,
should always be kept within
12.
CHAPTER
TWO
TROUBLESHOOTING
Troubleshooting motorcycle problems is
relatively simple. To be effective and efficient,
however, it must be done in a logical step-by-
it
step manner. If
may be wasted, good parts may be replaced un-
necessarily, and the true problem may never be
uncovered.
Always begin by defining the symptoms as
closely as possible. Then, analyze the symptoms
carefully so that you can make an intelligent
guess at the probable cause. Next, test the prob-
able cause and attempt to verify it; if it's not at
fault, analyze the symptoms once again, this
time eliminating the first probable cause. Con-
tinue on in this manner, a step at a time, until
the problem is solved.
At first, this approach may seem to be time
consuming, but you will soon discover that it's
not nearly so wasteful as a hit-or-miss method
that may never solve the problem. And just as
important, the methodical approach to
troubleshooting ensures that only those parts
that are defective will be replaced.
The troubleshooting procedures in this
chapter analyze typical symptoms and show
logical methods for isolating and correcting
trouble. They are not, however, the only
methods; there may be several approaches to a
given problem, but all good troubleshooting
methods have one thing in common
logical, systematic approach.
is not, a great deal of time
-
a
ENGINE
The entire engine must be considered when
trouble arises that is experienced as poor per-
formance or failure to start. The engine is more
than a combustion chamber, piston, and
crankshaft; it also includes a fuel delivery
system, an ignition system, and an exhaust
system.
Before beginning to troubleshoot any engine
problems, it's important to understand an
it
engine's operating requirements. First,
have a correctly metered mixture of gasoline
1).
and air (Figure
tight combustion chamber in which the mixture
can be compressed. And finally, it requires a
precisely timed spark to ignite the compressed
mixture. If one or more is missing, the engine
won't run, and if just one is deficient, the
engine will run poorly at best.
Of the three requirements, the precisely
timed spark
-
is most likely to be the culprit, with gadair
mixture (carburetion) second, and poor com-
pression the least likely.
STARTING DIFFICULTIES
Hard starting is probably the most common
motorcycle ailment, with a wide range of prob-
lems likely. Before delving into a reluctant or
non-starter, first determine, what has changed
Second, it must have an air-
-
provided by the ignition system
must
10
4-STROKE OPERATING PRINCIPLES
CHAPTER
TWO
TROUBLESHOOTING
11
since the motorcycle last started easily. For in-
stance, was the weather dry then and is it wet
now? Has the motorcycle been sitting in the
garage for a long time? Has it been ridden
many miles since it was last fueled?
Has starting become increasingly more dif-
ficult? This alone could indicate a number of
things that may be wrong but is usually
associated with normal wear of ignition and
engine components.
While it's not always possible to diagnose
trouble simply from a change of conditions,
this information can be helpful and at some
future time may uncover a recurring problem.
Fuel Delivery
Although it is the second most likely cause of
trouble, fuel delivery should be checked first
simply because it is the easiest.
First, check the tank to make sure there is
fuel in it. Then, disconnect the fuel hose at the
carburetor, open the valve and check for flow
(Figure
2).
If fuel does not flow freely make
sure the tank vent is clear. Next, check for
blockage in the line or valve. Remove the valve
and clean it as described in the fuel system
chapter.
If fuel flows from the'hose, reconnect it and
remove the float bowl from the carburetor,
open the valve and check for flow through the
float needle valve. If it does not flow freely
when the float is extended and then shut off
when the flow is gently raised, clean the car-
buretor as described in the fuel system chapter.
When fuel delivery is satisfactory, go on to
the ignition system.
Ignition
Remove the spark plug from the cylinder and
check its condition. The appearance of the plug
is a good indication of what's happening in the
combustion chamber; for instance, if the plug is
wet with gas, it's likely that engine is flooded.
Compare the spark plug to Figure
3.
Make cer-
tain the spark plug heat range is correct. A
"cold" plug makes starting difficult.
After checking the spark plug, reconnect it to
the high-tension lead and lay it on the cylinder
head so it makes good contact (Figure
4).
Then,
with the ignition switched on, crank the engine
several times and watch for a spark across the
plug electrodes. A fat, blue spark should be
visible. If there is no spark, or if the spark is
weak, substitute a good plug for the old one
and check again. If the spark has improved, the
old plug is faulty. If there was no change, keep
looking.
Make sure the ignition switch is not shorted
to ground. Remove the spark plug cap from the
end of the high-tension lead and hold the ex-
)/8
posed end of the lead about
inch from the
cylinder head. Crank the engine and watch for
a spark arcing from the lead to the head. If it's
satisfactory, the connection between the lead
and the cap was faulty. If the spark hasn't im-
proved, check the coil wire connections.
If the spark is still weak, remove the ignition
cover and remove any dirt or moisture from'the
points or sensor. Check the point or air gap
against the specifications in the
Data
Reference
at the beginning of the book.
Quick
If spark is. still not satisfactory, a more
serious problem exists than can be corrected
with simple adjustments. Refer to the electrical
system chapter for detailed information for
correcting major ignition problems.
Compression
Compression
-
or the lack of it - is the
least likely cause of starting trouble. However,
if compression is unsatisfactory, more than a
simple adjustment is required to correct it (see
the engine chapter).
An accurate compression check reveals a lot
about the condition of the engine. To perform
this test you need a compression gauge (see
Chapter One). The engine should be at
operating temperature for a fully accurate test,
if
but even a cold test will reveal
the starting
problem is compression.
Remove the spark plug and screw in a com-
pression gauge (Figure
5).
With assistance, hold
the throttle wide open and crank the engine
several times, until the gauge ceases to rise.
Normal compression should be
a reading as low as
100
psi is usually sufficient
130-160
psi, but
for the engine to start. If the reading is much
lower than normal, remove the gauge and pour
about a tablespoon of oil into the cylinder.
12
CHAPTER
'IWO
TROUBLESHOOTING
13
w
lORMAL
Appearance-Firing tip has de-
ios~ts of light gray to light tan
Can be cleaned, regapped and
eused
:ARBON FOULED
Appearance-Dull dry black w~th
luffy carbon depos~ts on the in
ulator tip electrode and exposed
hell
Caused by-Fuellair m~xture too
ch plug heat range too cold
teak ignition system dirty air
leaner faulty automatic choke or
xcesslve Idling
Can be cleaned regapped and
eused
31L FOULED
Appearance-Wet black depos~ts
In insulator and exposed shell
Caused by-Excessive oil enter-
ng the combust~on chamber
hrough worn rlngs pistons valve
gdes or bear~ngs
1
Replace with new plugs (use a
latter plug if engine 18 not re
)aired)
OIL AND LEAD FOULED
Appearance-Glazed yellow de
pos~ts w~th a sl~ght brown~sh tint
on the insulator tip and ground
electrode
Replace with new plugs
FUEL ADDITIVE RESIDUE
Appearance - Brown colored
hardened ash deposits on the insu
lator t~p and ground electrode
Caused by-Fuel andlor oil addi-
t~ves
Replace w~th new plugs
WORN
Appearance - Severely worn or
eroded electrodes
Caused by-Normal wear or
unusual 011 andlor fuel add~tives
Replace w~th new plugs
PREIGNITION
Appearance - Melted ground
electrode
Caused by-Overadvanced ignl
tion timing inoperative ignhtion
advance mechanism too low of a
fuel octane rating lean fuellair
m~xture or carbon deposits in com-
bustion chamber
LEAD FOULED
Appearance - Yellow mulator
deposits (may sometimes be dark
gray black or tan in color) on the
insulator t~p
Caused by-Highly leaded gaso-
lhne
Replace with new plugs
LEAD FOULED
Appearance-Yellow glazed de-
pos~ts indcat~ng melted lead de-
posits due to hard acceleration
Caused by-Highly leaded gas@
line
Replace with new plugs
PREIGNITION
Appearance-Melted center elec.
trade
Caused by-Abnormal combus-
tion due to overadvanced ignit~on
tim~ng or ~ncorrect advance too
low of a fuel octane rating lean
fuellair mixture or carbon de-
posits In combustion chamber
Correct engine problem and
replace with new plugs
INCORRECT HEAT RANGE
Appearance-Melted center elec-
trode and white blistered ~nsulator
tip
Caused by-Incorrect plug heat
range select~on
Replace w~th new plugs
14
CHAPTER
TWO
IGNITION:
Turn switches on. Remove spark plug
and check for spark outside cyiinder
Refer to engine chepter
for
correction
Refer
to
electrical chapter for correction
t
TROUBLESHOOTING
15
Crank the engine several times to distribute the
it
oil and test the compression once again. If
is
now significantly higher, the rings and bore are
worn. If the compression did not change, the
valves are not seating correctly. Adjust the
valves and check again. If the compression is
still low, refer to the engine chapter.
NOTE:
developing problem. The condition
causing it should be corrected as soon as
possible.
Low compression indicates
a
POOR PERFORMANCE
Poor engine performance can be caused by
any of a number of things related to carbure-
tion, ignition, and the condition of the sliding
and rotating components in the engine. In addi-
tion, components such as brakes, clutch, and
transmission can cause problems that seem to
be related to engine performance, even when
the engine is in top running condition.
Poor Idling
Idling that is erratic, too high, or too low is
most often caused by incorrect adjustment of
the carburetor idle circuit. Also, a dirty air
filter or an obstructed fuel tank vent can affect
idle speed. Incorrect ignition timing or worn or
faulty ignition components are also good
possibilities.
First, make sure the air filter is clean and cor-
rectly installed. Then, adjust the throttle cable
free play, the throttle stop screw, and the idle
mixture air screw
(Figure
6)
as described in the
routine maintenance chapter.
If idling is still poor, check the carburetor
and manifold mounts for leaks; with the engine
warmed up and running, spray
WD-40
or a
similar light lube around the flanges and joints
of the carburetor and manifold
(Figure
7).
Listen for changes in engine speed. If a leak is
present, the idle speed will drop as the lube
it
"plugs" the leak and then pick up again as
is
drawn into the engine. Tighten the nuts and
clamps and test again. If a leak persists, check
for a damaged gasket or a pinhole in the mani-
fold. Minor leaks in manifold hoses can be
repaired with silicone sealer, but if cracks or
holes are extensive, the manifold should be
replaced.
16
A
worn throttle slide may cause erratic run-
ning and idling, but this is likely only after
many thousands of miles of use. To check,
remove the carburetor top and feel for back
and forth movement of the slide in the bore; it
should be barely perceptible. Inspect the slide
for large worn areas and replace it if it is less
than perfect
(Figure
8).
If the fuel system is satisfactory, check igni-
tion timing and breaker point gap (air gap in
electronic ignition). Check the condition of the
system components as well. Ignition-caused idl-
ing problems such as erratic running can be the
fault of marginal components. See the electrical
system chapter for appropriate tests.
Rough Running or Misfiring
Misfiring (see
Figure
9)
is usually caused by
an ignition problem. First, check all ignition
connections
(Figure
10).
They should be clean,
dry, and tight. Don't forget the kill switch; a
loose connection can create an intermittent
short.
CHAPTER
TWO
TROUBLESHOOTING
17
ENGINE RUNS ROUGH
AND
MISFIRES
Handlebar
(kill) switch
Main switch
ENGINE MISSESALL SPEEDS
f
Check ignition wire connections.
+Inspect the insulation on the spark plug high.
tension lead for cracking and deterioration.
+Inspect the spark plug for correct heat range
and condition.
+Check the point gap and the spring tension on
the contact breaker or check electronic module
on models with electronic ignition.
ENGINE MISSES AT LOW SPEED
+Check ignition system (above).
+Clean carburetor-pay particular attention to
low-speed jet and circuit.
ENGINE MISSES AT MID-RANGE
+Check ign~t~on system (above).
+Clean carburetor.
+
Check pos~tion and cond~tion
of slide needle.
.-+
0
-
AT HIGH SPEED
18
CHAPTER
TWO
Check the insulation on the high-tension
spark plug lead. If it is cracked or deteriorated
it
will allow the spark to short to ground when
the engine is revved. This is easily seen at night.
If arcing occurs, hold the affected area of the
wire away from the metal to which it is arcing,
using an insulated screwdriver
(Figure
ll),
and
see if the misfiring ceases. If it does, replace the
high-tension lead. Also check the connection of
the spark plug cap to the lead. If it is poor, the
spark will break down at this point when the
engine speed is increased.
The spark plug could also be poor. Test the
system with a new plug.
Incorrect point gap or a weak contact
breaker spring can cause misfiring. Check the
gap and the alignment of the points. Push the
moveable arm back and check for spring ten-
sion
(Figure
12).
It should feel stiff.
'
On models with electronic ignition, have the
electronic module tested by a dealer or sub-
stitute a known good unit for a suspected one.
If misfiring occurs only at a certain point in
engine speed, the problem may very likely be
TROUBLESHOOTING
19
IDLE/ LOW-SPEED
:
-
-
Needle
jet
\I
MID-RANGE
20
LOSS
OF
POWER
Handlebar (kill) switch
Gradual
V
Check ignition and carburetion and tune
engine if necessary.
Check compression. If compression rises
following wet test, ring and cylinder wear is
indicated. If compression remains low during
wet test, valve and seat wear are indicated.
Check brake adjustment and condition; they
may be dragging.
CHAPTER
TWO
Main switch
W
Sudden
Check wheel bearings for dirt, dryness, and
wear that may create drag.
module
Check compression (above). If power
sudden, damage
valves and seats are more likely than wear.
Check the ignition system for a failed
component, poor contact, or change in timing
or point gap. Check electronic module on
electronic ignition.
Check the fuel system for an obstruction.
to
rings, piston, and bore or
loss
is
carburetion. Poor performance at idle is
described earlier. Misfiring at low speed (just
above idle) can be caused by a dirty low-speed
circuit or jet
(Figure
13).
Poor midrange per-
formance is attributable to a worn or incor-
rectly adjusted needle and needle jet. Misfiring
at high speed (if not ignition related) is usually
caused by a too-large main jet which causes the
engine to run rich. Any of these carburetor-
related conditions can be corrected by first
it
cleaning the carburetor and then adjusting
as
described in the tune-up and maintenance
chapter.
Loss of
Power
First determine how the power loss developed
(Figure
14).
Did it decline over a long period of
time or did it drop abruptly? A gradual loss is
normal, caused by deterioration of the engine's
state of tune and the normal wear of the
cylinder and piston rings and the valves and
seats. In such case, check the condition of the
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