Linhai 2005 ATV 260, Service Manual

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CHAPTER 3B ENGINE 50cc/80cc
ATV SERVICE MANUAL07.0
CHAPTER 3B ENGINE PAGE 3B - 7 -
IN 4.975-4.990 4.9
Valve bar outer diameter
EX 4.955-4.970 4.9
IN 5.0-5.012 5.3 Valve guide pipe inner
diameter EX 5.0-5.012 5.3
IN 0.010-0.037 0.08 Gap between valve bar and
guide pipe
EX 0.030-0.057 0.10
Inner spring 30.5 26.1
Valve spring
Outer spring 33.5 30.5
Torque Value
Camshaft bolt 20N.m 15 ft
.
lbs lubricate threads with oil
Valve gap adjusting screw cap 8N. m 6 ft
.
lbs
Tools:
General tools
Valve spring compressor 45° IN/EX
Valve seat reamer 24.5mm Plane reamer 30° IN
Valve seat reamer 25mm Plane reamer 32° EX
Valve seat reamer 22mm Plane reamer 60° IN/ EX
Valve seat reamer 26mm
Reamer damping fixture 5mm
Special tools
Valve spring compressor accessories
Valve gap regulatory spanner
Valve guide screwdriver
Valve guide reamer
Trouble diagnosis
●
Confirm poor operation of cylinder head by
measuring pressure or by noise produced by
engine upper end.
Slow speed hitch White smoke from exhaust pipe
●
too low compression pressure
●
wearing of valve guide
●
bad valve gap
●
broken oil seal
●
burning or curving of valve Abnormal noise
●
bad valve timing
●
bad valve gap
●
broken valve spring
●
broken or burning of valve or valve spring
●
bad valve seat
●
wearing and breaking of camshaft
●
leakage of cylinder head gasket
●
wearing of inner chain adjusting plate
●
cylinder head surface warping or cracking
●
wearing of camshaft and valve rocker arm
●
bad spark plug
Too high compressed pressure
●
too much carbon build-up in combustion
chamber