Derbi GPR 125 Racing, Workshop Manual

Page: 164 / 247

5 - FUEL SUPPLY SYSTEM
164
5.3 - CHECKING LEVEL OF THE FLOAT CHAMBER
- Fit the carburettor tilted as in the figure.
- Check that the reference mark on the float is parallel with
the flat joining surface of the bowl.
- If other positions are detected, modify the positioning of
the metal needle control plate until the indicated position is
obtained.
VOLUME OF FUEL WITH THE
CORRECT FLOAT CHAMBER
LEVEL: 33-35 ml.
5.4 - CHECKING THE VACUM VALVE AND TAPERED NEEDLE
- Check that the vacuum valve needle is not worn.
- Check that the vacuum valve needle shows no sign of scra-
tching on its outer surface.
- Check that the vacuum supply hole is not obstructed.
- Check that the membrane is not broken or hardened. If it
is, renew the whole valve.
- Insert the needle into the valve housing.
MAKE OF NEEDLE: NDYD
DIAMETER OF NEEDLE:
2.49mm
- Refit the vacuum fuel valve in the carburettor body, taking
care that the needle enters inside the atomiser.
THE VALVE CAN ONLY BE IN-
SERTED IN ONE POSITION.
N.B.
N.B.
N.B.