Crankcase
The crankcase consist of two parts connected and
tightened with 6 screws of equal lenght and diameter,
and fixed to each other by two dowel pins.
Because of the fact that the two parts have been
machined connected together, replacement of one of
the parts is not possible.
When the engine comes to working temperature the
aluminum housing will expand more than the steel crank-
shaft bearings fitted in the crankcase. To prevent
rotating of the bearings in the housing, the diameter of
the crankcase bores is smaller than the outside diameter
of the ball
bearings.-
Before demounting the crankcase, loosen and remove
the 6 screws. To prevent the crankcase bores from
inrreparable damage it is necessary to heat the housing
parts up to about
100°C
(212°F) by means of a Bunsen
burner or a hot plate of 2000 W.
An easy way to check the temperature is to spit on the
housing.
Immediate evaporation means the housing has
reached the right temperature.
Seize the housing at two cylinder studs of the same
crankcase half, using a rag or gloves, and separate both
parts by tapping all around the outside of the housing,
using a plastic hammer.
Never hammer on the crankshaft!!
Before assembling the crankcase the parts also have to
be heated up to about 100°C (212°F).
Start with that part in which the dowel pins are fitted to
assure a correct position of the gasket. Before fitting the
gasket the joint surface should be oiled.
Next insert the crankshaft, clutch side first, into the
crankcase. Heat the other part and join both parts.
Then fit the 6 housing screws. After being tightened this
operation has to be repeated when the crankcase has
cooled down sufficiently.
Oil seals
Once a housing has been dismantled it is recommen-
dable
to fit new oil seals.
In
c|se
of leakage this must be done.
How^o
find a leak oil seal?:
Put the piston in T.D.C. to be sure that all ports of the
cylinder are closed.
Pull of the carburettor from the induction pipe.
A leak now can be determined by blowing smoke into
the induction pipe.
When fitting the oil seals alsways use tool nr.
48.50.11
respectively nr. 48.50.12 together wiht tool nr. 48.50.01
to prevent any damage of the oil seals and to be sure that
the seals are in the correct position.
10.76
To Next Page
Loading...