Service Manual
ENGINE
44
3. When replacin
g
reeds, install smooth ed
g
e down
centered over openin
g
s in crankcase (see Fi
g
ure
78), and use Loctite 271 on threads of screws.
Torque per specifications.
Figure 78
0720-020
Reassembly
Assemble the piston and connectin
g
rod. Note the
piston has the letters EX and an arrow stamped into
the top. The arrow should point towards the exhaust
port. The connectin
g
rod can be assembled to the
piston two ways. As the rod is symmetrical, either way
is acceptable. We will phase in match marks on the
rod and rod caps. Some of the very early en
g
ines may
not have these marks. Use a permanent marker if
match marks are not visible.
1. Secure wrist pin usin
g
snap rin
g
. Make sure
square ed
g
e of snap rin
g
faces out and rin
g
openin
g
faces up (toward top of piston). (See
Fi
g
ure 79.)
Figure 79
0893-028
Install keystone piston ring in top groove with bevel
facin
g
up. The square bottom rin
g
can be installed
either way. Note that there are pins in the rin
g
g
rooves. The open ends of the rin
g
s must line up
with the pins.
3. Assemble ball bearin
g
s to crankshaft and install
crankshaft.
4. Note: One side of the paper is sticky; remove
paper carefully while installin
g
needle bearin
g
s.
There should be 32 needle bearin
g
s on the lower
connectin
g
rod. When reinstallin
g
ori
g
inal needle
bearin
g
s, use a little #2 bearin
g
g
rease to stick the
needles to the rod.
5. Install rod cap (A). Ensure that matin
g
marks are
ali
g
ned. Clean old screws (B) thorou
g
hly and
apply Loctite 271. (See Fi
g
ure 80.) Torque to
specifications.
Figure 80
0893-023
6.Oil parts. Use rin
g
compressor to install piston
with EX mark and arrow pointin
g
towards the
exhaust port. Install seals before fully seating the
crankshaft. Install new oil seals. Clean seal bore
with alcohol before installin
g
seals. Oil in the bore
may cause the seal to blow out when the engine
is hot.
B
A
Note: Ring Compressor P/N TOR 4089 (order
from OTC, see page 5 for address and phone).
used. Pistons have been plated and unplated.
Pistons have used two keystone rings and others
2.Several piston and ring combinations have been
used one semi-keystone and one standard ring.
The pistons made for one type of ring will not accept
the other type. However, any piston and ring
assembly can be used in any cylinder.