Operators Manual

52 - English
Repair instructions
Larger, harder particles that enter the engine
cause serious damage to the underside of the
piston skirt.
Cause: Action:
Air filter damaged or
missing.
Fit a new air filter.
Parts from the carbu-
rettor or intake system
have come loose and
entered the engine.
Regular service and
inspection.
Service tips
Defect: Action:
Broken cooling fins, damaged threads or sheared
bolts by the exhaust port.
In severe cases – replace the cylinder.
Repair the threads using Heli-Coil.
Seizure marks in the cylinder bore (especially by
the exhaust port).
Polish the damaged area using a fine grade
emery cloth so that the coating of aluminium
disappears.
With deep seizure score marks the piston and
cylinder should be replaced.
Surface coating in the cylinder bore worn out
(primarily at the top of the cylinder).
Replace the cylinder and piston.
The piston shows signs of seizure score marks Carefully polish the damaged area using a fine
file of fine grade emery cloth. Before the piston
is refitted the cylinder should be polished as
above. With deep score marks the piston and
cylinder should be replaced.
Piston ring burnt in its groove. Carefully loosen the piston rings and clean the
groove well before refitting. Carbon deposits in
the groove impair the important heat transfer
between the piston and cylinder.
NOTE!
Be careful with the lower edge of the piston
ring groove. If this is damaged, or if carbon
deposits remain, the compression pressure
can leak through.
Check the wear on the piston ring by placing it
in the lower part of the cylinder.
Bolts much too tight in the aluminium material. Position a suitable punch on the bolt head and
give a few sharp knocks with a hammer. If the
bolt still does not loosen, repeat the procedure.