Yamaha MM700A Manual page 116

der bore is worn. Because the cylinder bores
are hard-surfaced, resizing is not possible.
I f the cylinder bore is excessively worn, ei-
therreplace the cylinder or machine it to ac-
cept a cast iron liner. Only
machinist familiar with these products, the
required tools and high performance snow-
mobile application should perform installa-
tion o f a linez
Piston Installation
1. Before assembly, perform the inspection procedures to
make sure all worn or defective parts have been cleaned or
replaced. Clean all parts thoroughly before installation or
assembly.
2. Lubricate the piston pin needle bearing with oil and in-
stall it in the connecting rod.
3. Lubricate the piston pin with oil and install it into one
side of the piston.
NOTE
I f the original pistons are being reinstalled
they should have been marked to indicate
qualified
4. Place the piston over the connecting rod with the arrow
cast in the top of the piston (Figure 40) pointing toward
the front (exhaust side) of the engine. This is essential so
the ends of the piston rings are correctly positioned and do
not catch in the ports. Align the piston pin with the bearing
and push the pin into the piston until it is even with the pis-
ton pin clip grooves.
their original cylinder location (PTU, MAG
or CEN) and the direction
port. The manufacturer 3 mark (arrow) cast
into the piston should point to the exhaust
port as described in Step 4.
CAUTION
I f the piston pin does not slide in the piston
smoothly with handpressure, use a tool de-
scribed during Piston Removal to install the
piston pin (Figure 26). The pipe is not used
when installing the pin. Instead, insert the
threaded rod through the piston pin, pin
bearing, connecting rod andpiston. Place a
small washer and nut on the threaded rod at
the end, which extends from the piston pin.
Slide a large washer onto the opposite end
CHAPTER FOUR
the exhaust