JIMS Box 2 1208-1352 (all models of 120, 131, or 135 Alpha, Beta and Evo Mount Engines) User Manual
Page 11
555 Dawson Drive, Camarillo, CA 93012 Phone 805-482-6913 • Fax 805-482-7422
10
Rev I
8-12
No.1208-1352
A Division of Thiessen Products, INC
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• See Fig. 37 for proper front and rear piston ring placement.
This placement is very critical to piston installation, be cer-
tain you have duplicated ring position per the diagram or
piston and ring damage can occur.
Note: If you find it useful, take a magic marker and duplicate
the numbers from the diagram onto your piston. Be sure
you have the rear cylinder with the rear piston.
• Fit the piston ring compressor, with a light film of clean H-D 20W-50 oil,
over the piston just far enough to capture all the rings. See Fig. 38.
• Align the ring compressor’s handle with the smaller exhaust valve relief.
See Fig. 39.
• Tighten the compressor.
• Confirm all rings are compressed. See Fig. 39.
• Lube skirt with assembly lube, and slide the piston, into the bore of the
cylinder. See Fig. 40.
• Place the ring compressors handle opposite the larger cylinder spigot
notch. See Fig. 40.
• Be careful to avoid damaging the piston skirts.
• Carefully push the piston into the bore with the palm of your gloved
hand. The ring compressor will release when the piston is completely in
the bore. See Fig. 41
• Turn each piston to the right and left approximately one (1) inch, this
movement should be smooth.
Assembly: Front Piston/Cylinder
• Use the same assembly technique as the above steps. Go back to step 7
and perform the same steps for other cylinder and piston.
• Be sure you have the Front piston with the Front cylinder.
Note: If you are not going to install the cylinders on your lower end assem
bly at this time you must bag the cylinders using one of the supplied
clean plastic bags.
STEP 8: Cylinder Installation
Note: This step is best done by two people.
Fig.37 - Arrange ring gaps in this pattern
Fig.38 - Proper ring
clamping
Fig.39 Compress rings
Fig.41 - Use hand to push
Fig.40 Lube & slide