Note: Prior to adjusting the engine idling speed, the carburetor synchronization should be adjusted properly, the air filter should be clean, and the engine should have adequate compression.
1. Start the engine and let it warm up for several minutes.
2. Remove: cylinder head cover (1)
![](https://motoinstruction.ru/img/yamaha/16/122177.jpg)
3. Install: engine tachometer (to the spark plug lead of cyl. #1)
- Engine tachometer: 90890-03113
![](https://motoinstruction.ru/img/yamaha/16/122178.jpg)
4. Check: engine idling speed
Out of specification → Adjust.
- Engine idling speed: 950-1050 r/min
5. Adjust: engine idling speed
a. Turn the pilot screw (1) in until it is lightly seated.
b. Turn the pilot screw out the specified number of turns.
![](https://motoinstruction.ru/img/yamaha/16/122179.jpg)
- Pilot screw: 3 turns out
c. Turn the throttle stop screw (2) in direction (a) or (b) until the specified engine idling speed is obtained.
![](https://motoinstruction.ru/img/yamaha/16/122180.jpg)
- Direction (a): Engine idling speed is increased.
- Direction (b): Engine idling speed is decreased.
6. Adjust: throttle cable free play. Refer to "Adjusting the throttle cable free play".
- Throttle cable free play (at the flange of the throttle grip): 4-6 mm