Check the cam contact surfaces for scratches, grooves, steps and waving.
Worn cams are frequently the cause of poor timing, which leads to loss of engine power.
Place the camshaft between two centres and check the run-out on the areas indicated using two dial gauges.
Service limit: 0.1 Mm.

Visually inspect the camshaft tracks for scoring and abnormal wear. If any of the above defects are found, the camshaft should be renewed.
If you find scoring or excessive wear, check the operation of the engine lubrication circuit.



Removal of the camshafts
Refitting the camshaftsReassembling the clutch
Position the spacer (13).
Fit the flat ring (11) and the belleville washer (10) on the clutch center
(12), so that the convex side faces the clutch
drum.
Locate the belleville washer (8).
Apply the prescribed grease to the thread of the gearbox primary shaft and
the mating surfac ...
Refitting the oil pump
If removed, apply specific threadlocker on the bushing (7) outer thread, and
screw it in the crankcase half, observing the
height.
Position the reference bushings (15) and the oil sealing o-rings (2) and (4)
according to the crankcase lubrication
channels.
Position the oil pump on th ...
Removal of the starter motor idler gear
Slide the gear pin (21) complete with the gear (19) and washer (20).
Warning
Pay attention to the washer (20) since it may fall inside the
crankcase half.
At this point, it is possible to remove the starter motor as described in
sect. 6 - 3, Starter motor. ...