Changhe FREEDOM CH6390 Series 2005 Service Manual page 77

CHANGHE FREEDOM SERVICE MANUAL
Fig. 3-059
Item
Top
Ring
ring
clearance in
2nd
the groove
ring
To measure the end gap, insert the piston ring into the cylinder bore, locating it at the lowest part of
the bore and holding it true and square; then use a thickness gauge to measure the gap. If the gap
measured exceeds the limit, replace the piston ring.
Piston ring end gap:
Item
Top ring
Piston
2nd ring
ring end
gap
Oil ring
Connecting rods
Big-end thrust clearance:
Check the big end of each connecting rod for thrust clearance, with the rod fitted and connected to
its crank pin in the normal manner. If the clearance measured is found to exceed the limit, the connecting
rod or the crankshaft, whichever is responsible for the excessive clearance, must be replaced.
Standard Limit
0.03~0.07mm 0.12mm
0.02~0.06mm 0.1m
Standard
0.15～0.3mm
0.7mm
0.15～0.35mm 0.7mm
0.25～0.7mm 1.8mm
Piston
ring
thickness
Ring
groove
width
Limit
73
ENGINE MECHANICAL
Top ring 1.47～1.49mm
2nd ring 1.47～1.49mm
Oil ring 2.75～2.8mm
Top ring 1.52～1.54mm
2nd ring 1.51～1.53mm
Oil ring 2.81～2.83mm
Fig. 3-060