Linhai 2004 ATV 260, Service Manual

Page: 131 / 362

CHAPTER 3B ENGINE 50cc/80cc
ATV SERVICE MANUAL09.0
CHAPTER 3B ENGINE PAGE 3B - 13 -
pry out valve guide pipe
Be careful to not damage cylinder head
Surface.
Press in the new valve guide pipe.
Spread engine oil on new O-ring and build up
new valve guide pipe.
Make sure cylinder head is still warm when
pressing in new guides.
Size valve guide with reamer after installing.
·
Use cutting oil on reamer.
·
Rotate reamer in proper direction and do not
stop rotation to push in or pull out.
Clean cylinder head and get rid of cut bits of
metal and dust.
Special tools
Valve guide pipe reamer
Valve seat checking and correcting
Valve seat checking
Get rid of carbon deposit from combustion
chamber and valves.
Spread emery on seat surface between valve
and valve seat.
Use polishing bar to wear-in valve.
Take out valve and check valve seat surface.
Change if valve surface is coarse or facial
polished.
Valve seat surface width checking.
Used limit: above 1.8mm correct.
Correct valve seat by chamfered tool if
surface width is not even or too wide and too
narrow.
Valve seat chamfer cutting tools
Refer to valve chamfered tool handbook for
detailed.
Press and rotate with 4-5 kg (10-12lb) force
to polish and cut when correcting.
Use chamfered tool after spreading engine
oil on it.