KYMCO Mongoose 90 Service Manual page 141

8
. CYLINDER/PISTON
PISTON RING INSPECTION
Measure each piston ring end gap.
Service Limits: Top/Second
0.4 mm (0.016 in)
＊
Set each piston ring squarely into the
cylinder using the piston and measure
the end gap.
CONNECTING ROD SMALL END
INSPECTION
Install the piston pin and bearing in the
connecting rod small end and check for
excessive play.
Measure the connecting road small end I.D.
Service Limit: 17.03 mm (0.6812 in)
PISTON/CYLINDER INSTALLATION
First install the expander in the second ring
groove.
Then install the top and second rings in their
respective ring grooves.
The piston rings should be pressed into the
grooves with even force.
After installation, check and make sure that
each ring is flush with the piston at several
points around the ring.
A ring that will not compress means that the
ring groove has carbon deposits in it and
should be cleaned.
8-17
Piston
Top Ring (1st Ring)
Second Ring
Expander