Cylinder Head; Centrifugal Shaft; Centrifugal Sprocket; Exhaust Valve Needle Cages - GAS GAS Enduro Series Workshop Manual

Workshop manual
SeRVICING aND RePaIRING THe eNGINe'S COmPONeNTS

CYLINDER HEAD

- Check that the cylinder head support surface is not deformed with respect to
the cylinder.
- Carefully clean the inside of the cylinder head; it must be free of carbon.
REMOVE
- Remove the screws
- Extract the bearings with an extractor along with the washer and the left-hand
exhaust valve.
- Remove the long exhaust valve shaft.
- Through the housing of the left-hand exhaust valve, dislodge the right-hand
exhaust valve, spacer and bearing -8- by tapping gently with a hammer.
- Remove the shaft from the short exhaust valve by tapping gently with a
hammer inside the screw hole.
- Remove the central exhaust valve through the exhaust port of the cylinder.
Note:
Toremovethecentrifuge,simplycompressspring-19-tothepinandremoveit.
CHECK

Centrifugal shaft

- Check that the centrifugal shaft does not show signs of jamming or oxidation.
The hood must slide smoothly over the shaft.

Centrifugal sprocket

- Check that the sprocket does not show signs of wear in the toothed contact
area.

Exhaust valve needle cages

- Check that the needle cages do not show signs of jamming or hardness when
rotating and that the plates have no grooves.
Centrifugal balls
- Check the condition of the centrifugal balls. They must remain spherical in
shape and show no signs of wear or contact marks.
Diameter of the centrifugal balls
Needle
- Check that it is firmly attached to the centrifugal outlet lever.
- If it is necessary to remove it, mark its position with respect to the centrifugal
lever shaft, e.g. with an indelible marker.
-33-
8 mm