Piston - CPI SuperMoto Series Service Manual

PISTON AND CYLINDER
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 several areas of the tread, each
staggered by 90°.
Limit value: 0.03 mm

PISTON

Keep the piston on position and remove the circlip
of the piston pin with a suitable tool by holding it
on one side.
Then 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 cicrclips fall
into the engine.
The piston must not have any rougher signs of
scores or wear.
Carefully clean the piston top and the ring grooves
from any combustion residues. Pay attention not to
damage the ring or the grooves. Check the piston
pin and the needle bearing for wear.
Measure the outside diameter of the piston with a
micrometer calliper at a distance of approx. 5 mm,
measured from the edge of the piston. The
maximum clearance between piston and cylinder
must not exceed the defined limit value.
In case of deviations from the limit value both the
piston and cylinder have to be replaced.
Limit value: 0.1 mm
PC-5