Adjusting The Pilot Screw - Yamaha F100C Service Manual

FUEL

Adjusting the pilot screw

1. Start the engine and warm it up for 5 min-
utes to check the stability of the engine.
Adjust the pilot screw if necessary.
2. Attach the special service tool to high-
tension cord #1 1.
Digital tachometer: 90890-06760
3. Turn the pilot screws 2 in direction a
until the engine
decreased to approximately 40 r/min,
then in direction b 3/4 turn.
Engine idle speed: 800–900 r/min
4-19
Fuel system
S60C4290
idle speed has
S60C4300
4. Turn the throttle stop screw 3 in direc-
tion c or d until the specified engine
idle speed is obtained.
NOTE:
• To increase the idle speed, turn the throttle
stop screw in direction c.
• To decrease the idle speed, turn the throttle
stop screw in direction d.
5. After adjusting the idle speed, rev the
engine a few times and let it idle for at
least 15 seconds to check the stability of
the engine. Adjust the carburetor syn-
chronization if necessary.
S60C4310
60C5D11