engine YAMAHA BRUIN 250 2005 Workshop Manual

8-53 1. Locknut 2. Adjusting bolt
a. Throttle lever free play
1. Contre-écrou 2. Boulon de réglage
a. Jeu du levier d’accélération
1. Contratuerca 2. Perno de ajuste
a. Juego libre de la palanca del acelerador
EBU00303
Valve clearance adjustment
The correct valve clearance changes with use, re-
sulting in improper fuel/air supply or engine noise.
To prevent this, the valve clearance must be ad-
justed regularly. This adjustment however, should
be left to a professional Yamaha service techni-
cian.
EBU00307
Throttle lever adjustmentNOTE:Adjust the engine idling speed before adjusting the
throttle lever free play.1. Loosen the locknut.
2. Turn the adjusting bolt until the throttle lever
free play is 3.0–5.0 mm.
3. Tighten the locknut.
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8-77
EBU00570
Cable inspection and lubrication
WARNING
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the outer cov-
ering of control cables becomes damaged.
Cables can also become frayed or kinked. Op-
eration of controls could be restricted, which
could cause an accident or injury. Lubricate the inner cables and the cable ends. If
the cables do not operate smoothly, ask a Yamaha
dealer to replace them.
Recommended lubricant:
Engine oil
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8-105
EBU00440Troubleshooting chart
1. Fuel
Check if there is fuel
in the fuel tank.There is fuel.Turn the fuel cock
lever to “OFF”.
Turn the fuel cock
lever to “ON”. Remove the
fuel hose. No fuel.
Clean fuel
cock. Some fuel.Turn the fuel
cock to “RES”.Restart engine.
No fuel.Supply fuel.
2. Compression
Use electric starter to
see if there is
compression.There is compression.
Compression normal.
No compression.Ask a Yamaha dealer to
inspect.
3. Ignition
Remove spark plug and
check electrodes.
WetWipe clean with dry cloth.
DryAttach spark plug cap and
ground to chassis.Use the
electric starter.Spark good.Ignition system
normal.
Spark weak.
Adjust plug gap
or replace plug. No spark.
Ask a Yamaha dealer to
inspect. 4. Battery
Use electric starter.Engine turns over
quickly.Battery good.
Engine turns over
slowly.Check fluid, recharge,
check connections.Check fuel
flow.
Fuel cock
clogged.
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9-1
EBU00420
1-CLEANING AND STORAGE
A. CLEANING
Frequent, thorough cleaning of your machine will
not only enhance its appearance but will improve
its general performance and extend the useful life
of many components.
1. Before cleaning the machine:
a. Block off the end of the exhaust pipe to pre-
vent water entry. A plastic bag and strong
rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, ap-
ply degreaser with a paint brush. Do not ap-
ply degreaser to the wheel axles.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the
job.
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9-5
7. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or protec-
tive finish.
When finished, start the engine and let it idle for
several minutes.
WARNING
Wet brakes may have reduced stopping ability,
increasing the chance of an accident. Test the
brakes after washing. Apply the brakes several
times at slow speeds to let friction dry out the
linings.
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9-7
EBU00427
B. STORAGE
Long term storage (60 days or more) of your ma-
chine will require some preventive procedures to
guard against deterioration. After thoroughly
cleaning the machine, prepare for storage as fol-
lows:
1. Fill the fuel tank with fresh fuel and add fuel
stabilizer (if available).NOTE:Use of fuel stabilizer eliminates the need to drain
the fuel system. Consult a Yamaha dealer if the
fuel system is to be drained instead.2. Remove the spark plug, pour about one ta-
blespoon of SAE 10W30 or 20W40 motor oil
in the spark plug hole and reinstall the spark
plug. Ground the spark plug wire and turn the
engine over several times to coat the cylinder
wall with oil.
3. Lubricate all control cables.
4. Block up the frame to raise all wheels off the
ground.
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10-1
EBU00428
SPECIFICATIONS
Model YFM250B
Dimension:
Overall length 1,916 mm
Overall width 1,038 mm
Overall height 1,118 mm
Seat height 772 mm
Wheelbase 1,170 mm
Minimum ground clearance 150 mm
Minimum turning radius 2,900 mm
Basic weight:
With oil and full fuel tank 216.0 kg
Noise and vibration level:
Noise level (77/311/EEC) (For Europe) 77.5 dB (A)
Vibration on seat (EN1032, ISO5008)
(For Europe) Will not exceed 0.5 (m/s
2)
Vibration on handlebar (EN1032, ISO5008)
(For Europe) Will not exceed 2.5 (m/s2)
Engine:
Type Air-cooled 4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 229.6 cm
3
Bore
× stroke 71.0
× 58.0 mm
Compression ratio 8.70:1
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10-2
10
Starting system Electric starter and recoil starter
Lubrication system Wet sump
Engine oil:
Type
Recommended engine oil classification: API Service SE, SF, SG type or higher
Quantity:
Without oil filter element removal 1.50 L
With oil filter element removal 1.60 LModel YFM250B
-20˚ -10˚ 0˚
10˚20˚ 30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
CAUTION:
In order to prevent clutch slippage (since the en-
gine oil also lubricates the clutch), do not mix any
chemical additives. Do not use oils with a diesel
specification of “CD” or oils of a higher quality
than specified. In addition, do not use oils labeled
“ENERGY CONSERVING II” or higher.
U1P060.book Page 2 Monday, August 2, 2004 12:19 PM