PERIODIC MAINTENANCE AND ADJUSTMENT

EAU42110

Adjusting the carburetor

The carburetor is an important part of the engine and requires very sophisticated adjustment. Therefore, most carburetor adjustments should be left to a Yamaha dealer, who has the necessary professional knowledge and experience. The adjustment described in the following section, however, may be serviced by the owner as part of routine maintenance.

Notice

The carburetor has been set and extensively tested at the Yamaha factory. Changing these settings without sufficient technical knowledge may result in poor performance of or damage to the engine.

EAU44390

Adjusting the engine idling speed

The engine idling speed must be adjusted when necessary.

1.Start the engine and thoroughly warm it up.

2.Turn the throttle stop screw until the engine runs at the lowest possible speed.

3.To increase the engine idling speed, turn the throttle stop screw in direction (a). To decrease the engine idling speed, turn the throttle stop screw in direction (b).

Adjusting the throttle cable free play

1.Throttle stop screw

1.Throttle cable free play

The throttle cable free play should measure 3.0–5.0 mm (0.12–0.20 in) at the throttle grip. Periodically check the throttle cable free play and, if necessary, adjust it as follows.

Tip

The engine idling speed must be correctly adjusted before checking and adjusting the throttle cable free play.

1.Loosen the locknut.

2.To increase the throttle cable free play, turn the adjusting nut in direction (a). To decrease the throttle cable free play, turn the adjusting nut in direction (b).