check engine light YAMAHA WR 250F 2012 Owners Manual

CONTENTS
CHAPTER 1
GENERAL INFOR-
MATION
LOCATION OF
IMPORTANT LABELS ..... 1-1
DESCRIPTION ................. 1-5
CONSUMER
INFORMATION................. 1-6
INCLUDED PARTS .......... 1-6
IMPORTANT
INFORMATION................. 1-6
CHECKING OF
CONNECTION .................. 1-7
SPECIAL TOOLS ............. 1-8
CONTROL FUNCTIONS.. 1-12
MULTI-FUNCTION
DISPLAY ........................ 1-13
STARTING AND
BREAK-IN ...................... 1-18
TORQUE-CHECK
POINTS........................... 1-20
CLEANING AND
STORAGE ...................... 1-21
CHAPTER 2
SPECIFICATIONS
GENERAL
SPECIFICATIONS ............ 2-1
MAINTENANCE
SPECIFICATIONS ............ 2-3
TIGHTENING
TORQUES ...................... 2-12
LUBRICATION
DIAGRAMS .................... 2-19
CABLE ROUTING
DIAGRAM ....................... 2-21
CHAPTER 3
REGULAR INSPEC-
TION AND AD-
JUSTMENTS
PERIODIC MAINTENANCE
CHART FOR THE EMISSION
CONTROL SYSTEM (For
Canada) ............................ 3-1
GENERAL MAINTENANCE
AND LUBRICATION CHART
(For Canada) .................... 3-2
MAINTENANCE INTER-
VALS FOR COMPETITION
USE ................................... 3-3
PRE-OPERATION
INSPECTION AND
MAINTENANCE................ 3-7
ENGINE ............................ 3-8
CHASSIS ........................ 3-19
ELECTRICAL ................. 3-29
CHAPTER 4
TUNING
ENGINE
(Except for Canada) ........ 4-1
CHASSIS .......................... 4-5
CHAPTER 5
ENGINE
RADIATOR ....................... 5-1
CARBURETOR................. 5-4
AIR INDICTOIN
SYSTEM ......................... 5-12
CAMSHAFTS.................. 5-14
CYLINDER HEAD........... 5-19
VALVES AND VALVE
SPRINGS ........................ 5-21
CYLINDER AND
PISTON ........................... 5-25
CLUTCH ......................... 5-29OIL FILTER ELEMENT
AND WATER PUMP .......5-34
BALANCER ....................5-39
OIL PUMP .......................5-41
KICK SHAFT AND SHIFT
SHAFT ............................5-44
AC MAGNETO AND
STARTER CLUTCH........5-49
ENGINE REMOVAL........5-54
CRANKCASE AND
CRANKSHAFT ...............5-58
TRANSMISSION,
SHIFT CAM AND
SHIFT FORK ...................5-64
CHAPTER 6
CHASSIS
FRONT WHEEL AND
REAR WHEEL ..................6-1
FRONT BRAKE AND
REAR BRAKE ..................6-6
FRONT FORK .................6-16
HANDLEBAR..................6-23
STEERING ......................6-27
SWINGARM ....................6-31
REAR SHOCK
ABSORBER ....................6-36
CHAPTER 7
ELECTRICAL
ELECTRICAL COMPO-
NENTS AND WIRING
DIAGRAM .........................7-1
IGNITION SYSTEM...........7-3
ELECTRIC STARTING
SYSTEM............................7-5
CHARGING SYSTEM .....7-13
THROTTLE POSITION
SENSOR SYSTEM .........7-15
LIGHTING SYSTEM .......7-18
SIGNALING SYSTEM.....7-20

1-5
DESCRIPTION
DESCRIPTION
• The machine you have purchased may differ slightly from those shown in the following.
• Designs and specifications are subject to change without notice.
1. Clutch lever
2. Hot starter lever
3. Engine stop switch
4. Multi-function display
5. Main switch
6. Start switch
7. Front brake lever
8. Throttle grip
9. Radiator cap
10. Fuel tank cap
11. Taillight
12. Kickstarter crank
13. Fuel tank14. Headlight
15. Radiator
16. Coolant drain bolt
17. Rear brake pedal
18. Valve joint
19. Fuel cock
20. Cold starter knob
21. Air cleaner
22. Catch tank
23. Drive chain
24. Oil level check window
25. Shift pedal
26. Front fork

3-3
MAINTENANCE INTERVALS FOR COMPETITION USE
• The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
• Hydraulic brake service
• After disassembling the brake master cylinders and calipers, always change the fluid. Regularly check the brake fluid
levels and fill the reservoirs as required.
• Every two years replace the internal components of the brake master cylinders and calipers, and change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.
MAINTENANCE INTERVALS FOR COMPETITION USE
• The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as
weather, terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals.
If you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer.
• Periodic inspection is essential in making full use of the machine performance. The service life of the parts varies sub-
stantially according to the environment in which the machine runs (e.g., rain, dirt, etc.). Therefore, earlier inspection is
required by reference to the list below.
15 Sidestand pivotCheck operation.

Apply lithium-soap-based grease (all-purpose
grease) lightly.
16 * Front forkCheck operation and for oil leakage.

Replace if necessary.
17 * Shock absorber assemblyCheck operation and for oil leakage.

Replace if necessary.
18 * Rear suspension link pivots Apply molybdenum disulfide grease lightly.
19 * Control cablesApply Yamaha chain and cable lube or engine
oil 10W-30 thoroughly.
20 * Throttle grip housing and cableCheck operation and free play.
 Adjust the throttle cable free play if necessary.
Lubricate the throttle grip housing and cable.
21 * Chassis fastenersCheck all chassis fitting and fasteners.

Correct if necessary.
22 Battery Check terminal for looseness and corrosion. No. ITEM CHECKS AND MAINTENANCE JOBSINITIALODOMETER
READINGS
600 mi
(1,000
km) or 1
month1,800 mi
(3,000
km) or 3
months3,000 mi
(5,000
km) or 6
months
ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks
ENGINE OIL
Replace●●
VALVES
Check the valve clearances●●The engine must be cold.
Inspect●Check the valve seats and valve
stems for wear.
Replace●
VALVE SPRINGS
Inspect●Check the free length and the tilt.
Replace●

3-15
ENGINE
5. Remove:
• Oil hose clamp "1"
• Bolt (oil hose)
• Oil hose "2"
• Oil strainer "3"
6. Inspect:
• Oil strainer
Clogged→Blow.
7. If the oil filter is to be replaced dur-
ing this oil change, remove the fol-
lowing parts and reinstall them.
Replacement steps:
a. Remove the oil filter element cov-
er "1" and oil filter element "2".
b. Check the O-rings "3", if cracked
or damaged, replace them with a
new one.
c. Install the oil filter element and oil
filter element cover.
8. Install:
• O-ring "1" • Oil strainer "2"
• Oil hose
• Bolt (oil hose)
• Oil hose clamp
9. Install:
• Copper washer
• Oil filter element drain bolt
• Crankcase oil drain bolt
• Oil tank drain bolt
• Engine guard
10. Fill:
• Engine oil11. Check:
• Oil leakage
12. Install:
• Oil filler cap
• Washer (oil tank)
• Bolt (oil tank)
13. Check:
• Engine oil level
CHECKING THE OIL PRESSURE
1. Check:
• Oil pressure
Checking steps:
a. Slightly loosen the oil pressure
check bolt "1".
b. Start the engine and keep it idling
until oil starts to seep from the oil
pressure check bolt. If no oil
comes out after one minute, turn
the engine off so it will not seize.
c. Check oil passages and oil pump
for damage or leakage.
d. Start the engine after solving the
problem(s) and recheck the oil
pressure.
e. Tighten the oil pressure check
bolt.
Oil filter element cover:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil strainer:
9 Nm (0.9 m•kg, 6.5
ft•lb)
Bolt (oil hose):
8 Nm (0.8 m•kg, 5.8
ft•lb)
Oil hose clamp:
2 Nm (0.2 m•kg, 1.4
ft•lb)
Oil filter element drain
bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Crankcase oil drain bolt:
20 Nm (2.0 m•kg, 14
ft•lb)
Oil tank drain bolt:
18 Nm (1.8 m•kg, 13
ft•lb)
Engine guard:
7 Nm (0.7 m•kg, 5.1
ft•lb)
Oil quantity:
Periodic oil change:
1.1 L (0.97 Imp qt, 1.16
US qt)
With oil filter replace-
ment:
1.2 L (1.06 Imp qt, 1.27
US qt)
Total amount:
1.4 L (1.23 Imp qt, 1.48
US qt)
Bolt (oil tank):
7 Nm (0.7 m•kg, 5.1
ft•lb)
Oil pressure check bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)

3-16
ENGINE
ADJUSTING THE PILOT SCREW
(For EUROPE)
1. Adjust:
• Pilot screw "1"
Adjustment steps:
To optimize the fuel flow at a smaller
throttle opening, each machine's pilot
screw has been individually set at the
factory. Before adjusting the pilot
screw, turn it in fully and count the
number of turns. Record this number
as the factory-set number of turns
out.
a. Turn in the pilot screw until it is
lightly seated.
b. Turn out the pilot screw by the
factory-set number of turns.
ADJUSTING THE ENGINE IDLING
SPEED
1. Start the engine and thoroughly
warm it up.
2. Adjust:
• Engine idling speed
Adjustment steps:
a. Turn the throttle stop screw "1"
until the specified engine idling
speed.
Using a digital engine tachometer for
idle speed adjustment, detect the en-
gine idling speed by bringing the
sensing element "c" of the engine ta-
chometer close to the ignition coil "2".
ADJUSTING THE VALVE
CLEARANCE
This section is intended for those who
have basic knowledge and skill con-
cerning the servicing of Yamaha mo-
torcycles (e.g., Yamaha dealers,
service engineers, etc.) Those who
have little knowledge and skill con-
cerning servicing are requested not to
undertake inspection, adjustment,
disassembly, or reassembly only by
reference to this manual. It may lead
to servicing trouble and mechanical
damage.
• The valve clearance should be ad-
justed when the engine is cool to
the touch.
• The piston must be at Top Dead
Center (T.D.C.) on compression
stroke to check or adjust the valve
clearance.
1. Remove:
•Seat
•Fuel tank
Refer to "SEAT, FUEL TANK
AND SIDE COVERS" section.
2. Drain:
• Coolant
Refer to "CHANGING THE
COOLANT" section.
3. Remove:
• Right radiator
Right to "RADIATOR" section in
the CHAPTER 5.
• Carburetor
Refer to "CARBURETOR" section
in the CHAPTER 5.
• Spark plug
• Upper engine bracket
• Cylinder head cover
Refer to "CAMSHAFTS" section
in the CHAPTER 5.4. Remove:
• Timing mark accessing screw "1"
• Crankshaft end accessing screw
"2"
• O-ring
5. Check:
• Valve clearance
Out of specification→Adjust.
Checking steps:
a. Turn the crankshaft counterclock-
wise with a wrench.
b. Align the T.D.C. mark "a" on the
rotor with the align mark "b" on the
crankcase cover when piston is at
T.D.C. on compression stroke.
In order to be sure that the piston is at
Top Dead Center, the punch mark "c"
on the exhaust camshaft and the
punch mark "d" on the intake cam-
shaft must align with the cylinder
head surface, as shown in the illustra-
tion.
c. Measure the valve clearance "e"
using a feeler gauge "1".
Record the measured reading if the
clearance is incorrect.
Pilot screw (example):
2 turns out
To increase idle speed→Turn the
throttle stop screw "1" in "a".
To decrease idle speed→Turn the
throttle stop screw "1" out "b".
Engine idling speed:
1,750–1,950 r/min
Valve clearance (cold):
Intake valve:
0.10–0.15 mm
(0.0039–0.0059 in)
Exhaust valve:
0.17–0.22 mm
(0.0067–0.0087 in)

3-19
CHASSIS
CLEANING THE SPARK
ARRESTER (For USA)
• Be sure the exhaust pipe and si-
lencer are cool before cleaning
the spark arrester.
• Do not start the engine when
cleaning the exhaust system.
1. Remove:
• Screw (silencer cap) "1"
2. Remove:
• Bolt (spark arrester) "1"
3. Remove:
• Tail pipe "1"
• Gasket (tail pipe) "2"
• Spark arrester "3"
Pull the spark arrester out of the
silencer.
• Gasket (spark arrester) "4"
4. Clean:
• Spark arrester
Tap the spark arrester lightly,
then use a wire brush to remove
any carbon deposits.
5. Install:
• Gasket (spark arrester)
• Spark arrester
Insert the spark arrester into the
silencer and align the bolt holes.
• Gasket (tail pipe)
• Bolt (spark arrester)6. Install:
• Silencer cap
First tighten the two screws "a" locat-
ed horizontally apart, and then tighten
the others.
CHASSIS
BLEEDING THE HYDRAULIC
BRAKE SYSTEM
Bleed the brake system if:
• The system has been disassem-
bled.
• A brake hose has been loosened
or removed.
• The brake fluid is very low.
• The brake operation is faulty.
A dangerous loss of braking per-
formance may occur if the brake
system is not properly bled.
1. Remove:
• Brake master cylinder cap
• Diaphragm
• Reservoir float (front brake)
• Protector (rear brake)
2. Bleed:
•Brake fluid
Air bleeding steps:
a. Add proper brake fluid to the res-
ervoir.
b. Install the diaphragm. Be careful
not to spill any fluid or allow the
reservoir to overflow.
c. Connect the clear plastic tube "2"
tightly to the caliper bleed screw
"1".A. Front
B. Rear
d. Place the other end of the tube
into a container.
e. Slowly apply the brake lever or
pedal several times.
f. Pull the lever in or push down on
the pedal. Hold the lever or pedal
in position.
g. Loosen the bleed screw and allow
the lever or pedal to travel to-
wards its limit.
h. Tighten the bleed screw when the
lever or pedal limit has been
reached; then release the lever or
pedal.
i. Repeat steps (e) to (h) until of the
air bubbles have been removed
from the system.
If bleeding is difficult, it may be nec-
essary to let the brake fluid system
stabilize for a few hours. Repeat the
bleeding procedure when the tiny
bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on
the reservoir.
Check the operation of the brake
after bleeding the brake system.
3. Install:
• Protector (rear brake)
• Reservoir float (front brake)
• Diaphragm
• Brake master cylinder cap
Bolt (spark arrester):
7 Nm (0.7 m•kg, 5.1
ft•lb)
Silencer cap:
5 Nm (0.5 m•kg, 3.6
ft•lb)
Bleed screw:
6 Nm (0.6 m•kg, 4.3
ft•lb)

3-27
CHASSIS
2. Inspect:
• Bearing free play
Exist play→Replace.
CHECKING AND ADJUSTING THE
STEERING HEAD
1. Place a stand under the engine to
raise the front wheel off the
ground. WARNING! Securely
support the vehicle so that
there is no danger of it falling
over.
2. Check:
• Steering stem
Grasp the bottom of the forks and
gently rock the fork assembly
back and forth.
Free play→Adjust steering head.
3. Check:
• Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action→Adjust steer-
ing ring nut.
4. Adjust:
• Steering ring nut
Steering ring nut adjustment
steps:
a. Remove the headlight.
b. Remove the handlebar and upper
bracket.
c. Loosen the steering ring nut "1"
using the steering nut wrench "2".d. Tighten the steering ring nut "3"
using steering nut wrench "4".
• Apply the lithium soap base grease
on the thread of the steering stem.
• Set the torque wrench to the steer-
ing nut wrench so that they form a
right angle.
e. Loosen the steering ring nut one
turn.
f. Retighten the steering ring nut us-
ing the steering nut wrench.
Avoid over-tightening.
g. Check the steering stem by turn-
ing it lock to lock. If there is any
binding, remove the steering stem
assembly and inspect the steer-
ing bearings.
h. Install the washer "5", collar "6",
upper bracket "7", washer "8",
steering stem nut "9", handlebar
"10", handlebar upper holder "11"
and headlight "12".
• Install the collar "6" with the larger
inside diameter facing downward.
• The handlebar upper holder should
be installed with the punched mark
"a" forward.
• Install the handlebar so that the
marks "b" are in place on both
sides.• Install the handlebar so that the pro-
jection "c" of the handlebar upper
holder is positioned at the mark on
the handlebar as shown.
• Insert the end of the fuel breather
hose "13" into the hole in the steer-
ing stem.
First tighten the bolts on the front
side of the handlebar upper holder,
and then tighten the bolts on the
rear side.
Steering nut wrench:
YU-33975/90890-01403
Steering nut wrench:
YU-33975/90890-01403
Steering ring nut (initial
tightening):
38 Nm (3.8 m•kg, 27
ft•lb)
Steering ring nut (final
tightening):
7 Nm (0.7 m•kg, 5.1
ft•lb)
Steering stem nut:
145 Nm (14.5 m•kg, 105
ft•lb)
Handlebar upper holder:
28 Nm (2.8 m•kg, 20
ft•lb)
Pinch bolt (upper brack-
et):
21 Nm (2.1 m•kg, 15
ft•lb)
Headlight:
7 Nm (0.7 m•kg, 5.1
ft•lb)

3-29
ELECTRICAL
ELECTRICAL
CHECKING THE SPARK PLUG
1. Remove:
• Spark plug
2. Inspect:
• Electrode "1"
Wear/damage→Replace.
• Insulator color "2"
Normal condition is a medium to
light tan color.
Distinctly different color→Check
the engine condition.
When the engine runs for many hours
at low speeds, the spark plug insula-
tor will become sooty, even if the en-
gine and carburetor are in good
operating condition.
3. Measure:
• Plug gap "a"
Use a wire gauge or thickness
gauge.
Out of specification→Regap.
4. Clean the plug with a spark plug
cleaner if necessary.
5. Tighten:
• Spark plug
• Before installing a spark plug, clean
the gasket surface and plug sur-
face.
• Finger-tighten "a" the spark plug
before torquing to specification "b".
CHECKING THE IGNITION TIMING
1. Remove:
• Timing mark accessing screw "1"
2. Attach:
• Timing light
• Digital tachometer
To the ignition coil lead (orange
lead"1").
3. Adjust:
• Engine idling speed
Refer to "ADJUSTING THE EN-
GINE IDLING SPEED" section.
4. Check:
• Ignition timing
Visually check the stationary
pointer "a" is within the firing
range "b" on the rotor.
Incorrect firing range→Check ro-
tor and pickup assembly.
5. Install:
• Timing mark accessing screwCHECKING AND CHARGING THE
BATTERY
Batteries generate explosive hy-
drogen gas and contain electrolyte
which is made of poisonous and
highly caustic sulfuric acid. There-
fore, always follow these preven-
tive measures:
• Wear protective eye gear when
handling or working near batter-
ies.
• Charge batteries in a well-venti-
lated area.
• Keep batteries away from fire,
sparks or open flames (e.g.,
welding equipment, lighted ciga-
rettes).
• DO NOT SMOKE when charging
or handling batteries.
• KEEP BATTERIES AND ELEC-
TROLYTE OUT OF REACH OF
CHILDREN.
• Avoid bodily contact with elec-
trolyte as it can cause severe
burns or permanent eye injury.
FIRST AID IN CASE OF BODILY
CONTACT:
EXTERNAL
• Skin — Wash with water.
• Eyes — Flush with water for 15
minutes and get immediate med-
ical attention.
INTERNAL
• Drink large quantities of water or
milk followed with milk of magne-
sia, beaten egg or vegetable oil.
Get immediate medical attention.
Charging time, charging amperage
and charging voltage for an MF
battery are different from those of
conventional batteries. The MF
battery should be charged as ex-
plained in the charging method il-
lustrations. If the battery is
overcharged, the electrolyte level
will drop considerably. Therefore,
take special care when charging
the battery.
Since MF batteries are sealed, it is
not possible to check the charge state
of the battery by measuring the spe-
cific gravity of the electrolyte. There-
fore, the charge of the battery has to
be checked by measuring the voltage
at the battery terminals.
Spark plug gap:
0.7–0.8 mm
(0.028–0.031 in)
Spark plug:
13 Nm (1.3 m•kg, 9.4
ft•lb)
Timing light:
YM-33277-A/90890-
03141

4-1
ENGINE (Except for Canada)
TUNING
ENGINE (Except for Canada)
CARBURETOR SETTING
• The air/fuel mixture will vary de-pending on atmospheric conditions.
Therefore, it is necessary to take
into consideration the air pressure,
ambient temperature, humidity,
etc., when adjusting the carburetor.
• Perform a test run to check for prop- er engine performance (e.g., throt-
tle response) and spark plug(-s)
discoloration or fouling. Use these
readings to determine the best pos-
sible carburetor setting.
It is recommended to keep a record of
all carburetor settings and external
conditions (e.g., atmospheric condi-
tions, track/surface conditions, lap
times) to make future carburetor set-
ting easier.
• The carburetor is a part of the fuel line. Therefore, be sure to in-
stall it in a wellventilated area,
away from flammable objects
and any sources of fire.
• Never look into the carburetor in- take. Flames may shoot out from
the pipe if the engine backfires
while it is being started. Gasoline
may be discharged from the ac-
celerator pump nozzle when the
carburetor has been removed.
• The carburetor is extremely sen-sitive to foreign matter (dirt,
sand, water, etc.). During instal-
lation, do not al low foreign mat-
ter to get into the carburetor.
• Always handle the carburetor and its components carefully.
Even slight scratches, bends or
damage to carburetor parts may
prevent the carburetor from
functioning correctly. Carefully
perform all servicing with the ap-
propriate tools and without ap-
plying excessive force.
• When the engine is stopped or when riding at no load, do not
open and close the throttle un-
necessarily. Otherwise, too
much fuel may be discharged,
starting may become difficult or
the engine may not run well. • After installing the carburetor,
check that the throttle operates
correctly and opens and closes
smoothly.
ATMOSPHERIC CONDITIONS AND
CARBURETOR SETTINGS
The air density (i.e., concentration of
oxygen in the air) determines the rich-
ness or leanness of the air/fuel mix-
ture.
• Higher temperature expands the air with its resultant reduced density.
• Higher humidity reduces the amount of oxygen in the air by so
much of the water vapor in the
same air.
• Lower atmospheric pressure (at a
high altitude) reduces the density of
the air.
EFFECT OF SETTING PARTS IN
RELATION TO THROTTLE VALVE
OPENING
A. Closed
B. Fully open
1. Pilot jet
2. Throttle valve cutaway
3. Jet needle
4. Main jet CONSTRUCTION OF
CARBURETOR AND SETTING
PARTS
The FLATCR carburetor has a prima-
ry main jet. This type of main jet is
perfect for racing machines since it
supplies an even flow of fuel, even at
full load. Use the main jet and the jet
needle to set the carburetor.
1. Jet needle
2. Pilot air jet
3. Needle jet
4. Main jet
5. Pilot jet
ADJUSTING THE MAIN JET
The richness of the air-fuel mixture at
full throttle can be set by changing the
main jet "1".
If the air-fuel mixture is too rich or too
lean, the engine power will drop, re-
sulting in poor acceleration.
Effects of changing the main jet
(reference)
A. Idle
B. Fully open
1. #180
2. #160
3. #170
Air
tem p. Hu-
midi- ty Air
pres- sure
(alti-
tude) Mix-
ture Set-
ting
High High Low
(high) Rich-
er Lean-
er
Low Low High
(low) Lean-
er Rich-
er
Standard main jet #170
* #160
* For EUROPE

5-17
CAMSHAFTS
4. Measure:
• Camshaft-to-cap clearance
Out of specification→Measure
camshaft outside diameter.
Measurement steps:
a. Install the camshaft onto the cylin-
der head.
b. Position a strip of Plastigauge
®
"1" onto the camshaft.
c. Install the clip, dowel pins and
camshaft caps.
• Tighten the bolts (camshaft cap) in
a crisscross pattern from innermost
to outer caps.
• Do not turn the camshaft when
measuring clearance with the
Plastigauge
®.
d. Remove the camshaft caps and
measure the width of the Plasti-
gauge
® "1".
5. Measure:
• Camshaft outside diameter "a"
Out of specification→Replace the
camshaft.
Within specification→Replace
camshaft case and camshaft
caps as a set.CHECKING THE CAMSHAFT
SPROCKET
1. Inspect:
• Camshaft sprocket "1"
Wear/damage→Replace the
camshaft assembly and timing
chain as a set.
CHECKING THE
DECOMPRESSION SYSTEM
1. Check:
• Decompression system
Checking steps:
a. Check that the decompression
mechanism cam "1" moves
smoothly.
b. Check that the decompression
mechanism cam lever pin "2" proj-
ects from the camshaft.
CHECKING THE TIMING CHAIN
TENSIONER
1. Check:
• While pressing the tensioner rod
lightly with fingers, use a thin
screwdriver "1" and wind the ten-
sioner rod up fully clockwise.
• When releasing the screwdriver
by pressing lightly with fingers,
make sure that the tensioner rod
will come out smoothly.
• If not, replace the tensioner as-
sembly.INSTALLING THE CAMSHAFT
1. Install:
• Exhaust camshaft "1"
• Intake camshaft "2"
Installation steps:
a. Turn the crankshaft counterclock-
wise with a wrench.
• Apply the molybdenum disulfide oil
on the camshafts.
• Apply the engine oil on the decom-
pression system.
• Squeezing the decompression le-
ver allows the crankshaft to be
turned easily.
b. Align the T.D.C. mark "a" on the
rotor with the align mark "b" on the
crankcase cover when piston is at
T.D.C. on compression stroke.
c. Fit the timing chain "3" onto both
camshaft sprockets and install the
camshafts on the cylinder head. Camshaft-to-cap clear-
ance:
0.028–0.062 mm
(0.0011–0.0024 in)
:0.08 mm (0.003
in)
Bolt (camshaft cap):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Camshaft outside diame-
ter:
21.959–21.972 mm
(0.8645–0.8650 in)