Yamaha F50A - Adjusting the Pilot Screw

62Y3A11
4-22
1
2
3
4
5
6
7
8
I
4. Push the throttle control lever
1
to the
fully open position as shown.
5. While pushing the carburetor throttle
lever
2
against the carburetor stopper
3
, loosen, and then tighten the adjusting
screw
5
.
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
.
3. Turn the pilot screws
2
in direction
a
until the engine idle speed has
decreased to approximately 50 r/min,
then in direction
b
5/8 turn.
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.
Inductive self-powered tachometer:
YU-08036-B
Digital tachometer: 90890-06760
S62Y4350
1
Engine idle speed: 900
±
50 r/min
Carburetor