21
WORKSHOP MANUAL
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2.8.
Joining the housing halves
Heat the right half of engine housing the same
way as the left one. Coat the left housing half sealing
surface with sealing putty. Coat the gearbox shaft end
and the right crank pin with oil. Engage the idling
between the 1
st
and 2
nd
gears and move the right
connecting rod in the top position to make it pass easier
through the housing slit. Mount the mid insert in the
housing mid recess. Heat the right housing half along
with all bearings as well as the countershaft needle
bearing well and join it as quickly as possible to the
other half – while turning the gear plus hub to get the
gears mate each other. Drive in the rear centring pin.
Bolt tightly the two housing halves together with M6
bolts (start with mod bolts). Tighten the bolts once
more after the housing is cool and clean the housing
vent hole.
Using a pipe of suitable diameter tap on the ball bearing
inner ring to achieve the true position of the balls in the
bearing runway. Lubricate the bearings with engine oil.
Drive on both crankshaft seal rings – before mounting
make sure that they are duly joined with each other.
Use S-72 drift for driving operation. Lock the seal rings
to prevent their shifting. Tap down slightly the mid
insert. For the next engine assembly steps clamp the
engine front section in the vice and proceed as decribed
above. Pour the oil into the gearbox as late as possible
to allow the sealing putty -between housing halves- dry
fully.
2.9.
Mounting the engine into the
frame
When mounting the engine in, proceed
in reverse sequence of the disassembly.
Before mounting the clutch disengaging
holder, coat the ball under the adjusting bolt
with grease. Once the engine is mounted in
the bike frame and clutch cable attached,
adjust the clutch release mechanism.