Yamaha F100C Service Manual page 92

FUEL
6. Turn the throttle valve adjusting screws
6 to adjust the vacuum pressure of car-
buretors #1, #2, and #3 to the same vac-
uum variation as carburetor #4.
#1
#2
#3
#4
7. Adjust the engine idle speed to specifica-
tion.
Engine idle speed: 800–900 r/min
8. After adjusting the idle speed, rev the
engine a few times and let it idle for at
least 15 seconds to check that the vac-
uum pressure of carburetors #1, #2, and
#3 stays within 50 mmHg (67 mbar, 1.97
inHg) of carburetor #4, and to check the
stability of the engine.
4-21
Fuel system
S60C4350
60C5D11