Piston Removal; Piston Inspection - Sym EuroMX 125 Service Manual

Piston Removal

Plug crankcase opening with a cleaning cloth to
prevent from piston pin snap ring or other parts
falling into crankcase when disassembling.
Hold another snap ring with pliers.
Push out the piston pin from the side that not
removed the snap ring.
Remove piston rings.
Caution
Pay attention to remove piston rings because
they are fragile.
Disassemble the piston rings.
Check if the piston rings are damaged or its
grooves are worn.
Clean out the carbon deposit around the
piston ring groove.

Piston Inspection

Install the piston rings and then measure
clearance between piston ring and its grooves.
Service Limit:
Top ring: replace if over 0.09 mm
nd
2 ring: replace if over 0.09 mm
Take out the piston rings and place them
respective into cylinder below 20mm of cylinder
top. Measure each piston ring gaps.
Caution
Push the piston rings into cylinder with
piston top-end in parallel motion.
Service Limit:
Top ring: replace if over 0.5 mm
nd
2 ring: replace if over 0.65 mm
This Chapter Contents
7. Cylinder/Piston
Piston ring
Piston
Piston rings
Push in
Feeler gauge
7-5