Place the vehicle on a suitable stand.
2. Remove:
- Rider seat
Refer to "GENERAL CHASSIS".
- Fuel tank side covers
- Fueltank
Refer to "FUEL TANK".
- Air filter case
Refer to "AIR FILTER CASE".
3. Remove:
- Caps "1"
![](https://motoinstruction.ru/img/yamaha/20/126311.jpg)
4. Install:
- Vacuum gauge "1"
- Digital tachometer
Vacuum gauge 90890-03094. Carburetor synchronizer YU-44456. Digital tachometer 90890-06760 YU-39951-B.
![](https://motoinstruction.ru/img/yamaha/20/126312.jpg)
5. Install:
- Air filter case
Refer to "AIR FILTER CASE".
- Fuel tank
Refer to "FUEL TANK".
6. Check:
- Throttle body synchronization
a. Start the engine, warm it up for several minutes, and then let it run at the specified engine idling speed.
Engine idling speed 1150-1250 r/min.
b. Check the vacuum pressure.
The difference in vacuum pressure between the throttle bodies should not exceed 1.33 kPa (10 mmHg).
Only #2 is set 1.6 kPa (12 mmHg, 0.49 inHg) higher.
If out of specification → Adjust the throttle body synchronization.