Page 294 of 378
8-43 1. Adjusting bolt 2. Locknut a. 3 ~ 5 mm
1. Boulon de réglage 2. Contre-écrou
1. Perno de ajuste 2. Contratuerca
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 ~ 5 mm.
3. Tighten the locknut.
EE.book Page 43 Monday, June 25, 2001 2:27 PM
Page 300 of 378
8-49
5. Brake fluid may deteriorate painted surfaces
or plastic parts. Always clean up spilled fluid
immediately.
6. Have a Yamaha dealer check the cause if the
brake fluid level goes down.
EBU00820*
Brake fluid replacement
1. Complete fluid replacement should be done
only by trained Yamaha service personnel.
2. Have a Yamaha dealer replace the following
components during periodic maintenance or
when they are damaged or leaking.
Replace all rubber seals every two years.
Replace all hoses every four years.
EE.book Page 49 Monday, June 25, 2001 2:27 PM
Page 302 of 378
8-51 a. Free play
a. Jeu
a. Juego libre
EBU00681
Front brake adjustment
The front brake lever should have a free play of
zero mm at the lever end. If not, ask a Yamaha
dealer to adjust it.
WARNING
Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability
which could lead to an accident.
After servicing:
Make sure the brakes operate smoothly
and that the free play is correct.
Make sure the brakes do not drag.
Make sure the brakes are not spongy. All
air must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
EE.book Page 51 Monday, June 25, 2001 2:27 PM
Page 308 of 378
8-57 1. Locknut 2. Adjusting bolt a. 5 ~ 8 mm
1. Contre-écrou 2. Boulon de réglage
1. Contratuerca 2. Perno de ajuste
3. Turn the adjusting bolt until free play reaches
5 ~ 8 mm at the lever pivot.
4. Tighten the locknut.
WARNING
Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:
Make sure the brakes operate smoothly
and that the free play is correct.
Make sure the brakes do not drag.
Replacement of brake components re-
quires professional knowledge. These pro-
cedures should be performed by a Yamaha
dealer.
EE.book Page 57 Monday, June 25, 2001 2:27 PM
Page 340 of 378

8-89
EBU00413
Troubleshooting
Although Yamaha machines receive a rigid in-
spection before shipment from the factory, trouble
may occur during operation.
Any problem in the fuel, compression, or ignition
systems can cause poor starting and loss of pow-
er. The troubleshooting chart describes a quick,
easy procedure for making checks. If your ma-
chine requires any repair, take it to a Yamaha
dealer.
The skilled technicians at a Yamaha dealership
have the tools, experience, and know-how to prop-
erly service your machine. Use only genuine
Yamaha parts on your machine. Imitation parts
may look like Yamaha parts, but they are often in-
ferior. Consequently, they have a shorter service
life and can lead to expensive repair bills.
WARNING
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe in-
jury or property damage. Make sure there are
no open flames or sparks in the area, including
pilot lights from water heaters or furnaces.
EE.book Page 89 Monday, June 25, 2001 2:27 PM
Page 357 of 378
10-2
10
Engine:
Type Air-cooled 4-stroke, SOHC
Cylinder arrangement Single cylinder, forward-inclined
Displacement 229.6 cm
Bore
× stroke 71
× 58 mm
Compression ratio 8.7:1
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 higherModel YFM250X
-20˚-10˚0˚
10˚20˚30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
EE.book Page 2 Monday, June 25, 2001 2:27 PM
Page 363 of 378
10-8
Système de démarrage Démarreur électrique et à réenroulement
Système de graissage Carter humide
Huile de moteur:
Type
Classification d’huile de moteur recommandée API Service de type SE, SF, SG ou supérieur Modèle YFM250X
-20˚-10˚0˚
10˚20˚30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
ATTENTION:Veiller à ce que l’huile de moteur utilisée ne contien-
ne pas d’additifs antifriction. Les huiles pour auto-
mobiles (portant souvent la désignation “ENERGY
CONSERVING II”) contiennent des additifs anti-
friction. Ceux-ci feront patiner l’embrayage et/ou
l’embrayage de démarreur, ce qui provoquera une
réduction de la durabilité des organes et du rende-
ment.
EE.book Page 8 Monday, June 25, 2001 2:27 PM