44
Inspecting Camshaft Bearing
Journal
1. Inspect the bearing journal for scoring, seizure
marks, or pitting.
2. If excessive scoring, seizure marks, or pitting is
found, the cylinder head assembly must be replaced.
NOTE: If the journals are worn, replace the cam-
shaft.
Inspecting Camshaft
Spring/Unloader Pin
1. Inspect the spring and unloader pin for damage.
CF061A
NOTE: With the weight extended, the unloader pin
should be flat-side out; with the weight retracted, the
unloader pin should be round-side out.
CF060A
2. If damaged, the camshaft must be replaced.
Installing Top-Side
Components
A. Piston
B. Cylinder
1. Lubricate the piston pin, connecting rod, and piston
pin bore with motor oil; then install the piston on the
connecting rod making sure there is a circlip on each
side.
NOTE: The piston should be installed so the arrow
points towards the exhaust.
MD1213
2. Place the two alignment pins into position. Place a
new cylinder gasket into position; then place a piston
holder (or suitable substitute) beneath the piston skirt
and square the piston in respect to the crankcase.
MD1344
3. Lubricate the inside wall of the cylinder; then using a
ring compressor or the fingers, compress the rings
and slide the cylinder over the piston. Route the cam
chain up through the cylinder cam chain housing;
then remove the piston holder and seat the cylinder
firmly on the crankcase.
MD1345
4. Loosely install the two nuts securing the cylinder to
the right-side crankcase half.
CAUTION
The cylinder should slide on easily. Do not force the cyl-
inder or damage to the piston, rings, cylinder, or crank-
shaft assembly may occur.