12
Remove the wrist pin needle bearing from the connecting
rod.
Fault
Remedy
Broken cooling fins, damaged In serious cases - change the
threads or broken screw at
cylinder. Repair the thread
the exhaust port.
HeIi-Coil-inserts.
Seizure marks in the cylinder Grind the damaged spot with a fine
wall (especially at the exhaust emery cloth so that the adhered
port).
aluminum disappears. When
deeper seizure scratches occur,
the cylinder and piston should be
exchanged.
Surface coating in the cylinder Exchange the cylinder and piston.
wall worn (mainly at the top
of the cylinder).
The piston has seizure marks. Carefully grind the damaged spot
with a fine file or a emery cloth.
Before the piston is reassembled,
the cylinder should be grinded, as
above. When deeper scratches
occur, the piston should be
exchanged and also the cylinder,
if necessary.
The piston ring is stuck in its
Loosen the piston ring carefully
groove.
and clean the groove very carefully
before reassembly. Check the
piston ring for wear by placing it in
the bottom part of the cylinder.
Assembly
Clean the cylinder base to crankcase contact surfaces
making sure that all used gasket material is removed.
Position the new cylinder base gasket on the crankcase.
A small amount of grease maybe applied to hold the
gasket in place. Lubricate the wrist pin needle bearing
with oil and insert the bearing into the connecting rod
small end.
