Yamaha YB50 Service Manual page 96

CARBURETOR
4. Check:
• throttle valve
Wear/Damage
5. Check:
• throttle valve displacement
Irregular movement/Catches
Insert the throttle valve
and check its displacement.
6. Check:
• throttle stop screw
• pilot air screw
• jet needle
• starter plunger
Wear/Damage
7. Measure:
• Float height
Outside specifications
float and valve seat
Float height k a
15.0 mm ~ 17.0 mm
Steps for measuring the height of the float:
• Assemble the valve, float and axle on the
carburettor body
• Turn the carburettor upside down
• Using a vernier caliper, measure the distance
between the plane of the bowl gasket (wit-
hout the gasket) and the upper part of the
float.
5-4
CARB
Change
Change
in the body
Change
k
a
Check valve,