CPI ARAGON, Service Manual, Page: 59 / 93

CRANK DRIVE / CRANKCASE / CRANKSHAFT CR-4
Adjust the piston to the bottom dead center
before removing the cylinder.
Carefully remove the cylinder and the base
gasket.
Fill the opening of the engine with a rag in
order to avoid dirt or foreign material from
entering the crankcase.
The inside wall of the cylinder must not show
any rougher wear or scores.
The ovality of the tread must be below the
given limit value.
Take measurings at three different areas of the
tread, each staggered by 90°:
-
TDC ring area
-
Middle ring area
-
BDC ring area
Wear limit: 40.09 mm
PISTON DISASSEMBLY
Keep the piston on position and remove the
circlip of the piston pin with a suitable tool by
holding it on one side.
Press out the piston pin towards that side.
Remove the piston and remove the needle
bearing from the piston boss.
Fill the opening of the engine with
a rag to prevent that the circlips
fall into the engine.
Remove the piston rings.
Carefully clean the piston top, the piston ring
grooves and the piston rings from any
combustion residues.
Do not strain or break the piston
rings!