Yamaha F15A Service Manual page 128

INSP
ADJ
CONTROL SYSTEM
Measuring steps:
8 Start the engine and allow it to warm
up for several minutes.
8 Attach the engine tachometer to the
spark plug lead of cylinder #1.
Engine tachometer:
YU-8036-A/90890-06760
8 Measure the engine idling speed.
2. Adjust:
9 Engine idling speed
Adjusting steps:
8 Turn in the pilot screw 1 until it is
lightly seated and then turn it out 1-1/2
turns.
8 Turn the pilot screw in direction a or
b, no more than 1/2 of a turn in either
direction, until the engine idling speed
is at its highest.
Pilot screw setting:
F15A: 1-1/4 ± 1/2 turns out
F9.9C/FT9.9D:
1-1/2 ± 1/2 turms out
8 Turn the throttle stop screw in direc-
tion c or d until the specified engine
idling speed is obtained.
Direction c
Direction d
3-9
Engine idling speed is
increased.
Engine idling speed is
decreased.
E