Page 354 of 444
8-89
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.
U5KM61.book Page 89 Friday, July 26, 2002 11:13 AM
Page 364 of 444
8-99
EBU01186
Brake fluid replacement
Complete fluid replacement should be done only
by trained Yamaha service personnel. Have a
Yamaha dealer replace the following components
during periodic maintenance or when they are
damaged or leaking.
Replace the oil seals every two years.
Replace the brake hoses every four years.
U5KM61.book Page 99 Friday, July 26, 2002 11:13 AM
Page 366 of 444
8-101 a. Free play
a. Jeu
a. Juego libre
EBU01190
Front brake lever free play
The front brake lever should have a free play of
zero mm at the lever end. If not, have a Yamaha
dealer 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.
_
U5KM61.book Page 101 Friday, July 26, 2002 11:13 AM
Page 370 of 444
8-105 a. 72 mm
Rear brake pedal height adjustmentNOTE:_ Adjust the rear brake before inspecting the rear
brake pads. _The top of the brake pedal should be positioned
72 mm above the top of the footrest. 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.
All air must be bled from the brake sys-
tem.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
_
U5KM61.book Page 105 Friday, July 26, 2002 11:13 AM
Page 402 of 444

8-137
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.
U5KM61.book Page 137 Friday, July 26, 2002 11:13 AM
Page 421 of 444
10-2
10
Compression ratio 9.1 :1
Starting system Electric and recoil starter
Lubrication system Wet sump
Engine oil:
Type
Recommended engine oil classification API Service SE, SF, SG type or higherModel YFM660F
-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.
U5KM61.book Page 2 Friday, July 26, 2002 11:13 AM
Page 427 of 444
10-8
Taux de compression 9,1 : 1
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 YFM660F
-20˚-10˚0˚
10˚20˚30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
ATTENTION:
Ne pas mélanger d’additif chimique à l’huile afin d’éviter
tout patinage de l’embrayage, car l’huile moteur lubrifie
également l’embrayage. Ne pas utiliser des huiles de grade
diesel “CD” ni des huiles de grade supérieur à celui spéci-
fié. S’assurer également de ne pas utiliser une huile por-
tant la désignation “ENERGY CONSERVING II” ou la
même désignation avec un chiffre plus élevé.
U5KM61.book Page 8 Friday, July 26, 2002 11:13 AM