2012 YAMAHA WR 250F lock

2-13
TIGHTENING TORQUES
Throttle cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable (pull) M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable (return) M12 1 11 Nm (1.1 m•kg, 8.0 ft•lb)
Throttle cable cover M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter plunger M12 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Hot starter cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Air filter case M6 2 8 Nm (0.8 m•kg, 5.8 ft•lb)
Air filter joint and air filter case M5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Exhaust pipe M8 2 20 Nm (2.0 m•kg, 14 ft•lb)
△Exhaust pipe protector M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Silencer M8 2 30 Nm (3.0 m•kg, 22 ft•lb)
Silencer clamp M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Spark arrester M5 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
Silencer cap M5 6 5 Nm (0.5 m•kg, 3.6 ft•lb)
Air induction pipe M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Air induction pipe clamp M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Air cut-off valve assembly and bracket M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Bracket (air cut-off valve) and frame M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Crankcase M6 11 12 Nm (1.2 m•kg, 8.7 ft•lb)
Crankcase bearing stopper M6 11 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase bearing stopper (crankshaft) M6 4 14 Nm (1.4 m•kg, 10 ft•lb) Stake.
Left crankcase cover M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Idle gear cover (starter motor)M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Idle gear plate M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Right crankcase cover M6 6 10 Nm (1.0 m•kg, 7.2 ft•lb)
Clutch cover M6 7 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase oil drain bolt M10 1 20 Nm (2.0 m•kg, 14 ft•lb)Copper
washer
△Crankshaft end accessing screw M32 1 —
△Timing mark accessing screw M14 1 —
Drive chain sprocket cover M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Kick shaft ratchet wheel guide M6 2 12 Nm (1.2 m•kg, 8.7 ft•lb) Lock washer
Kickstarter crank M8 1 33 Nm (3.3 m•kg, 24 ft•lb)
Primary drive gear M18 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Clutch spring M6 5 10 Nm (1.0 m•kg, 7.2 ft•lb)
Clutch boss M16 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Clutch cable locknut M8 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Push lever shaft M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Drive sprocket M18 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Drive axle oil seal stopper M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Segment M8 1 30 Nm (3.0 m•kg, 22 ft•lb)
Shift guide M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Stopper lever M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Shift pedal M6 1 12 Nm (1.2 m•kg, 8.7 ft•lb)ItemThread
sizeQ'ty Tightening torque Remarks

2-14
TIGHTENING TORQUES
CHASSIS
△- marked portion shall be checked for torque tightening after break-in or before each race.
ItemThread
sizeQ'ty Tightening torque Remarks
△Upper bracket and outer tube M84 21 Nm (2.1 m•kg, 15 ft•lb)
△Lower bracket and outer tube M8 4 21 Nm (2.1 m•kg, 15 ft•lb)
△Upper bracket and steering stem M24 1 145 Nm (14.5 m•kg, 105 ft•lb)
△Handlebar upper holder and handlebar
lower holderM8 4 28 Nm (2.8 m•kg, 20 ft•lb)
△Handlebar lower holder and upper brack-
etM10 2 34 Nm (3.4 m•kg, 24 ft•lb)
△Steering stem and steering ring nut M28 1 Refer to TIP.
Front fork and front fork cap bolt M51 2 30 Nm (3.0 m•kg, 22 ft•lb)
Front fork and base valve M30 2 55 Nm (5.5 m•kg, 40 ft•lb)Copper
washer
Front fork cap bolt and damper rod M12 2 29 Nm (2.9 m•kg, 21 ft•lb)
Front fork bleed screw and front fork cap
boltM5 2 1 Nm (0.1 m•kg, 0.7 ft•lb)
△Front fork and front fork protector M6 6 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Front fork protector and brake hose hold-
erM6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Throttle grip cap M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Front brake master cylinder M6 29 Nm (0.9 m•kg, 6.5 ft•lb)
Brake lever mounting bolt M6 1 6 Nm (0.6 m•kg, 4.3 ft•lb)
Brake lever mounting nut M6 1 6 Nm (0.6 m•kg, 4.3 ft•lb)
Brake lever position locknut M6 1 5 Nm (0.5 m•kg, 3.6 ft•lb)
△Front brake hose guide and front brake
hose guide bracketM5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Front brake hose guide and lower bracket M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Clutch lever holder M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Clutch lever mounting nut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter lever holder M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter lever mounting nut M5 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Front brake master cylinder cap M4 2 2 Nm (0.2 m•kg, 1.4 ft•lb)
△
Front brake hose union bolt M10 2 30 Nm (3.0 m•kg, 22 ft•lb)Copper
washer
△Front brake caliper M8 2 23 Nm (2.3 m•kg, 17 ft•lb)
△Front brake caliper and brake hose holder M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Pad pin plug M10 2 3 Nm (0.3 m•kg, 2.2 ft•lb)
△Front brake caliper and pad pin M10 1 18 Nm (1.8 m•kg, 13 ft•lb)
△Rear brake caliper and pad pin M10 1 18 Nm (1.8 m•kg, 13 ft•lb)
△Brake caliper and bleed screw M8 2 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Front wheel axle and axle nut M16 1 90 Nm (9.0 m•kg, 65 ft•lb)
△Front wheel axle holder M8 4 21 Nm (2.1 m•kg, 15 ft•lb)
△Front brake disc M6 6 12 Nm (1.2 m•kg, 8.7 ft•lb)
△Rear brake disc M6 6 14 Nm (1.4 m•kg, 10 ft•lb)

2-15
TIGHTENING TORQUES
△Brake pedal M8 1 26 Nm (2.6 m•kg, 19 ft•lb)
△Rear brake master cylinder M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Rear brake master cylinder cap M4 2 2 Nm (0.2 m•kg, 1.4 ft•lb)
△
Rear brake hose union bolt M10 2 30 Nm (3.0 m•kg, 22 ft•lb)Copper
washer
△Rear wheel axle and axle nut M20 1 125 Nm (12.5 m•kg, 90 ft•lb)
△Nipple (spoke) — 72 3 Nm (0.3 m•kg, 2.2 ft•lb)
△Rear wheel sprocket M8 6 50 Nm (5.0 m•kg, 36 ft•lb)
△Rear brake disc cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Rear brake caliper protector M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Drive chain puller adjust bolt and locknut M8 2 19 Nm (1.9 m•kg, 13 ft•lb)
Engine mounting:
△Engine and engine bracket (front) M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Engine and frame (lower) M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Upper engine bracket and frame M8 4 34 Nm (3.4 m•kg, 24 ft•lb)
△Lower engine bracket and frame M8 4 34 Nm (3.4 m•kg, 24 ft•lb)
△Engine and engine bracket (upper) M10 1 55 Nm (5.5 m•kg, 40 ft•lb)
△Engine guard M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Regulator M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Pivot shaft and nut M16 1 85 Nm (8.5 m•kg, 61 ft•lb)
△Relay arm and swingarm M14 1 70 Nm (7.0 m•kg, 50 ft•lb)
△Relay arm and connecting rod M14 1 80 Nm (8.0 m•kg, 58 ft•lb)
△Connecting rod and frame M14 1 80 Nm (8.0 m•kg, 58 ft•lb)
△Rear shock absorber and frame M10 1 56 Nm (5.6 m•kg, 40 ft•lb)
△Rear shock absorber and relay arm M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Rear frame (upper) M8 1 38 Nm (3.8 m•kg, 27 ft•lb)
△Rear frame (lower) M8 2 32 Nm (3.2 m•kg, 23 ft•lb)
△Swingarm and brake hose holder M54 3 Nm (0.3 m•kg, 2.2 ft•lb)
Swingarm and patch M4 4 2 Nm (0.2 m•kg, 1.4 ft•lb)
Upper drive chain tensioner M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Lower drive chain tensioner M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Drive chain support M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Seal guard and swingarm M5 4 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Fuel tank M6 2 9 Nm (0.9 m•kg, 6.5 ft•lb)
△Fuel cock M6 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Seat set bracket and fuel tankM6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Fuel tank bracket and fuel tank M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Air scoop and fuel tank M6 6 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Air scoop and radiator guard (lower) M6 2 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Front fender M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Rear fender (front) M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Rear fender (rear) M6 2 11 Nm (1.1 m•kg, 8.0 ft•lb)
△Side cover M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Seat M8 2 22 Nm (2.2 m•kg, 16 ft•lb)ItemThread
sizeQ'ty Tightening torque Remarks

2-22
CABLE ROUTING DIAGRAM
A. Insert the end of the fuel tank
breather hose into the hole in
the steering stem.
B. Fasten the throttle cable, hot
starter cable and rectifier/regula-
tor lead onto the frame. Locate
the clamp under the throttle ca-
ble on the right side of the frame,
and face its ends, as well as the
tie ends, downward.
C. Fasten the diode (at the mark-
ing), throttle cable and hot start-
er cable onto the frame. Locate
the clamp end facing toward the
lower right of the frame and with
the tie end facing downward.
D. Fasten the wire harness, throttle
position sensor lead, starter mo-
tor lead and negative battery
lead onto the frame. Pass the
clamp through the hole in the
stay (air cut-off valve). Locate
the clamp end facing toward the
lower side of the frame and cut
off the tie end.
E. Pass the carburetor breather
hoses, carburetor overflow hose
and catch tank breather hose
between the connecting rod and
cross tube (frame).
F. Fasten the neutral switch lead
and oil hose together with the
plastic locking ties and cut off
the tie ends.
G. Fasten the neutral switch lead
and AC magneto lead onto the
frame. Locate the clamp end
facing toward the outside of the
frame and tie end facing toward
the rear of the frame.
H. Pass the clutch cable through
the cable guide.
I. Fasten the starter motor lead,
AC magneto lead and neutral
switch lead onto the frame. Lo-
cate the clamp end facing to-
ward the rear of the frame and
cut off the tie end.
J. Fasten the clutch cable, starter
motor lead, negative battery
lead, AC magneto lead and neu-
tral switch lead onto the frame.
Locate the clamp end facing to-
ward the rear of the frame and
cut off the tie end.
K. Pass the neutral switch lead and
AC magneto lead on the inside
of the wire harness.
L. Fasten the clutch cable, AC
magneto lead and neutral switch
lead onto the frame. Locate the
clamp end near the clutch cable
and cut off the tie end.M. Pass the clutch cable and wire
harness through the cable
guide.
N. Locate the couplers in the frame
recess.
O. Pass the carburetor breather
hoses, carburetor overflow hose
and catch tank breather hose so
that the hoses do not contact the
rear shock absorber.
P. Secure the coupler by pushing it
into the hole in the headlight
unit.
Q. Fasten the throttle position sen-
sor lead and the hot starter ca-
ble.
R. Locate the clamp between the
hot starter cable protector and
rubber cap.

3-11
ENGINE
CHECKING THE SILENCER AND
EXHAUST PIPE
1. Inspect:
• Gasket "1"
Damage→Replace.
INSTALLING THE SILENCER AND
EXHAUST PIPE
1. Install:
• Gasket
• Exhaust pipe "1"
• Nut (exhaust pipe) "2"
First, temporarily install both nuts,
then tighten either of these nuts to 13
Nm (1.3 m•kg, 9.4 ft•lb) and the other
to 20 Nm (2.0 m•kg, 14 ft•lb), and
then come back to the first one and
retighten it to 20 Nm (2.0 m•kg, 14
ft•lb).
2. Install:
• Silencer clamp "1"
• Gasket "2"
• Silencer "3"
• Washer "4"
• Bolt (silencer) "5"CHECKING THE COOLANT LEVEL
Do not remove the radiator cap
"1", drain bolt and hoses when the
engine and radiator are hot. Scald-
ing hot fluid and steam may be
blown out under pressure, which
could cause serious injury. When
the engine has cooled, place a
thick towel over the radiator cap,
slowly rotate the cap counter-
clockwise to the detent. This pro-
cedure allows any residual
pressure to escape. When the
hissing sound has stopped, press
down on the cap while turning
counterclockwise and remove it.
Hard water or salt water is harmful
to the engine parts. You may use
distilled water, if you can't get soft
water.
1. Place the machine on a level
place, and hold it in an upright po-
sition.
2. Remove:
• Radiator cap
3. Check:
• Coolant level "a"
Coolant level low→Add coolant.
1. RadiatorCHANGING THE COOLANT
Do not remove the radiator cap
when the engine is hot.
Take care so that coolant does not
splash on painted surfaces. If it
splashes, wash it away with water.
1. Place a container under the en-
gine.
2. Remove:
• Seat
• Left side cover
3. Remove the catch tank hose from
the catch tank and drain the tank
of its coolant.
4. Remove:
• Coolant drain bolt "1"
5. Remove:
• Radiator cap
Drain the coolant completely.
6. Clean:
• Cooling system
Thoroughly flush the cooling sys-
tem with clean tap water.
7. Install:
• Copper washer
• Coolant drain bolt
8. Fill:
•Radiator
• Engine
To specified level. Nut (exhaust pipe):
20 Nm (2.0 m•kg, 14
ft•lb)
Silencer clamp:
16 Nm (1.6 m•kg, 11
ft•lb)
Bolt (silencer):
30 Nm (3.0 m•kg, 22
ft•lb)
Coolant drain bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Recommended coolant:
High quality ethylene
glycol anti-freeze con-
taining anti-corrosion
for aluminum engine
Coolant "1" and water
(soft water) "2" mixing ra-
tio:
50%/50%
Coolant capacity:
0.99 L (0.87 Imp qt, 1.05
US qt)

3-12
ENGINE
• Do not mix more than one type of
ethylene glycol antifreeze con-
taining corrosion inhibitors for
aluminum engine.
• Do not use water containing im-
purities or oil.
Handling notes of coolant:
The coolant is harmful so it should be
handled with special care.
• When coolant splashes to your
eye.
Thoroughly wash your eye with
water and see your doctor.
• When coolant splashes to your
clothes.
Quickly wash it away with water
and then with soap.
• When coolant is swallowed.
Quickly make him vomit and take
him to a doctor.
9. Install:
• Radiator cap
Start the engine and warm it up
for a several minutes.
10. Check:
• Coolant level
Coolant level low→Add coolant.
CHECKING THE RADIATOR CAP
1. Inspect:
• Seal (radiator cap) "1"
• Valve and valve seat "2"
Crack/damage→Replace.
Exist fur deposits "3" →Clean or
replace.CHECKING THE RADIATOR CAP
OPENING PRESSURE
1. Attach:
• Radiator cap tester "1" and adapt-
er "2"
Apply water on the radiator cap seal.
3. Radiator cap
2. Apply the specified pressure.
3. Inspect:
•Pressure
Impossible to maintain the speci-
fied pressure for 10 seconds→
Replace.
CHECKING THE COOLING
SYSTEM
1. Inspect:
• Coolant level
2. Attach:
• Radiator cap tester "1" and adapt-
er "2"
3. Apply the specified pressure.
• Do not apply pressure more than
specified pressure.
• Radiator should be filled fully.
4. Inspect:
• Pressure
Impossible to maintain the speci-
fied pressure for 10 seconds→
Repair.
•Radiator "1"
• Radiator hose joint "2"
Coolant leakage→Repair or re-
place.
• Radiator hose "3"
Swelling→Replace.
ADJUSTING THE CLUTCH CABLE
FREE PLAY
1. Check:
• Clutch lever free play "a"
Out of specification→Adjust.
2. Adjust:
• Clutch lever free play
Clutch lever free play adjustment
steps:
a. Loosen the locknuts "1".
b. Adjust the free play by changing
their tightening position.
c. Tighten the locknuts.
• Make minute adjustment on the le-
ver side using the adjuster "2".
• After adjustment, check proper op-
eration of clutch lever.
Radiator cap tester:
YU-24460-01/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
Radiator cap opening
pressure:
110 kPa (1.1 kg/cm
2,
15.6 psi)
Radiator cap tester:
YU-24460-01/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
Standard pressure:
180 kPa (1.8 kg/cm
2,
25.6 psi)
Clutch lever free play "a"
:
8–13 mm (0.31–0.51 in)
Locknut:
7 Nm (0.7 m•kg, 5.1
ft•lb)

3-13
ENGINE
ADJUSTING THE THROTTLE GRIP
FREE PLAY
1. Check:
• Throttle grip free play "a"
Out of specification→Adjust.
2. Adjust:
• Throttle grip free play
Adjustment steps:
a. Slide the adjuster cover.
b. Loosen the locknut "1".
c. Turn the adjuster "2" until the
specified free play is obtained.
d. Tighten the locknut.
Prior to adjusting throttle grip free
play, the engine idling speed should
be adjusted.
After adjusting the throttle grip
free play, turn the handlebar to the
right and to the left to ensure that
this does not cause the engine
idling speed to change.
LUBRICATING THE THROTTLE
1. Remove:
• Cover (throttle cable cap) "1"
• Cover (grip cap) "2"
• Throttle grip cap "3"
2. Apply:
• Lithium soap base grease
On the throttle cable end "a".
3. Install:
• Throttle grip cap
• Screw (throttle grip cap)
• Cover (grip cap)
• Cover (throttle cable cap)
ADJUSTING THE HOT STARTER
LEVER FREE PLAY
1. Check:
• Hot starter lever free play "a"
Out of specification→Adjust.
2. Adjust:
• Hot starter lever free play
Hot starter lever free play adjust-
ment steps:
a. Loosen the locknut "1".
b. Turn the adjuster "2" until free
play "a" is within the specified lim-
its.
c. Tighten the locknut.
After adjustment, check proper oper-
ation of hot starter.
CLEANING THE AIR FILTER
ELEMENT
Proper air filter maintenance is the
biggest key to preventing premature
engine wear and damage.
Never run the engine without the
air filter element in place; this
would allow dirt and dust to enter
the engine and cause rapid wear
and possible engine damage.
1. Open the air filter case cover "1"
Loosen the quick screw "2" and pull
on it to open the air filter case cover.
2. Unhook:
•Binder "1"
3. Remove:
• Air filter element "1"
• Air filter guide "2" Throttle grip free play
"a":
3–5 mm (0.12–0.20 in)
Locknut:
4 Nm (0.4 m•kg, 2.9
ft•lb)
Screw (throttle grip cap):
4 Nm (0.4 m•kg, 2.9
ft•lb)
Hot starter lever free play
"a":
3–6 mm (0.12–0.24 in)
Locknut:
4 Nm (0.4 m•kg, 2.9
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)