Adjusting The Dash-Pot (Acceleration Pump) - Yamaha FT50C Service Manual

FUEL
Vacuum gauge (digital)
(commercially obtainable) 3:
Vacuum gauge (4 analog meters)
(commercially obtainable) 4:
Vacuum gauge adaptor
(commercially obtainable) 5:
4. Adjust the idle speed to 1,000 r/min by
turning the throttle stop screw 4 on car-
buretor #4 in direction a or b.
NOTE:
• To increase idle speed, turn the throttle
stop screw in direction a.
• To decrease idle speed, turn the throttle
stop screw in direction b.
5. Measure the vacuum pressure of carbu-
retor #4.
4-15
Fuel system
6. Turn the throttle valve adjusting screws
5 to adjust the vacuum pressure of car-
buretors #1, #2, and #3 to the same vac-
uum variation as carburetor #4.
7. Adjust the engine idle speed to specifica-
tion.
Engine idle speed: 850–950 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 pressures stay within 50 mm Hg
(67 m bar, 1.97 in Hg) and to check the
stability of the engine.
Adjusting the dash-pot
(acceleration pump)
1. Start the engine and warm it up for 5 min-
utes, and then check the engine speed at
the operation point of the dash-pot.
2. Attach the special service tool to high-
tension cord #1 1.
1
S62Y4430
62Y5A11