Yamaha RS90K Manuel D'atelier page 606

CARBURETORS AND FUEL PUMP
ASSEMBLY
NOTE:
• Before assembling the carburetors, wash all of
the parts in a petroleum based solvent.
• Always use a new gasket and O-rings.
1. Install:
2. Install:
a
b
NOTE:
Align the projection a on the piston valve dia-
phragm with the slot b in the carburetor body.
3. Measure:
Measurement and adjustment steps:
• Hold the carburetor upside down.
• Measure the distance between the carburetor
NOTE:
The float arm should resting on the needle valve
without exerting pressure on it.
• If the float height is not within specification,
• If either is worn, replace them both.
7-8
• Needle jet
• Pilot jet
• Main jet
• Pilot screw
Pilot screw:
2 turns out
• Jet needle
• Piston valve
• Piston valve spring
• Vacuum chamber cover
• Float height a
Out of specification → Adjust.
Float height:
16 mm (0.63 in)
body and top of the floats.
inspect the valve seat and needle valve.
CARB