Specifications

44
Chapter 1 Engine, clutch and gearbox
36.3e Fit new gasket and replace the cover
37 Replacing the camshaft, generator and left-hand casing
fittings
1 Turn the unit over and support it on wooden blocks with the
left-hand side uppermost. Fit the gauze crankcase strainer, its
spring and the large hexagon-headed cover. Push the neutral
indicator switch into position in the crankcase bore. It is
worthwhile ensuring that the rubber plug, which retains the
switch, is fitted to the outer casing, as this is easily overlooked.
2 The crankshaft pinion which drives the cam gear is marked
with a centre-punched timing dot. The crankshaft should be
rotated so that this mark is at the top, nearest to the cam gear.
The cam gear has a corresponding mark, and should be placed
in position so that these two marks correspond exactly. As long
as this precaution is observed, the valve timing will be set
correctly, but on no account overlook this setting as it is critical
to the operation of the engine.
3 Place the shim under the head of the cam gear shaft, then
fit the gear shaft in the crankcase bore, taking care that the 0
ring is not nipped as the head of the shaft enters its recess. The
head of the shaft should be positioned so that the small
projecting segment is uppermost; do not forget the small spring.
Fit the endfloat plunger in its bore, and depress it against spring
pressure while the retaining bolt is tightened.
4 Place the generator stator in position, noting the flat at the
top which engages with the head of the cam gear shaft. Ensure
that the rubber fillet through which the generator cables pass is
located correctly. The generator rotor can now be placed over
the mainshaft, and its securing nut tightened to a torque setting
of 4.0 - 5.0 kgf m (29 - 36 Ibf ft), having locked the crankshaft
in the same way as described during the removal sequence.
Route the neutral switch lead between the casting webs, noting
the rubber packing piece, and reconnect the end at the switch.
Make sure that the main output leads pass beneath the small
guide plate at the top of the casing.
38 Replacing the gearbox sprocket
1 Place the gearbox sprocket in position on the splined shaft
end, followed by the locking plate, which is similarly splined.
When the plate is aligned with the groove in the shaft, it can be
rotated sufficiently to allow the securing bolts to be fitted. Note
that if the rear chain was removed together with the sprocket,
this stage should be left until the engine has been installed in
the frame.
37.1a Refit gauze crankcase filter assembly
37.1b Do not omit rubber stop which retains neutral switch
37.2a Lower cam assembly into position