Advertisement
8. CYLINDER
HEAD/CYLINDER/PISTON
>
8-1
CYLINDER HEAD
DISASSEMBLY/
g1
ASSEMBLY
CYLINDER/PISTON REMOVAL/
INSTALLATION
SERVICE INFORMATION
TROUBLESHOOTING
CAMSHAFT
REMOVAL/INSTALLATION
8-2
CYLINDER HEAD
REMOVAL/
INSTALLATION
8-6
8-8
8-4
ft
SERVICE INFORMATION
Camshaft service
can be done
with the engine in the
frame.
Camshaft lubricating oil is fed through oil passages in the
cylinder head.
Clean
the oil passages
before
assembling the cyl¬
inder head. Fill the cylinder
head
oil pockets with
the clean engine oil
of the
proper
type
and
viscosity.
Clean all disassembled
parts
with
cleaning solvent and dry them by blowing
them off with
compressed air before inspec¬
tion.
Before reassembly,
lubricate the camshaft journals and
cam
lobes with
a
molybdenum oil solution.
When
disassembling, mark and
store
the disassembled
parts to
ensure that they
are reinstalled in their
proper
locations.
Be
careful
not to
damage the mating
surfaces
by
using a screwdriver when removing the
cylinder. Do
not
strike the cylin¬
der
too
hard during disassembly, even with
a
rubber
or
plastic mallet,
to prevent
the possibility of damage
to
the cylinder
fins.
Take care
not to
damage the cylinder walls
and pistons.
Store the valve and piston
components
in the same order they were installed so they can be reinstalled in the original
posi¬
tions.
>
E
■
TROUBLESHOOTING
ft
Engine top-end problems usually affect engine performance. These can
be diagnosed
by a compression or
leak down
test,
or
by
tracing noises in the top-end with
a
sounding rod
or
stethoscope.
If performance is poor
at
low
speeds, check for white smoke in the crankcase breather tube. If the tube is smokey, check for
seized piston rings.
NOTE
•
For cylinder compression and leak-down
test
procedures, refer
to
section 3
of the Common Service
Manual.
Excessive smoke
•
Worn valve
stem
or valve guide
•
Damaged
stem
seal
•
Worn cylinder,
piston or
piston rings
• Improper
installation
of piston rings
•
Scored or scratched
piston
or cylinder wall
Rough idle
•
Low
cylinder compression
Low
compression
•
Incorrect valve shim
adjustment (page
3-5)
•
Burned
or
bent valves
• Incorrect
valve timing
•
Broken valve spring
*
Uneven valve
seating
• Leaking
or damaged
head gasket
• Warped
or
cracked
cylinder
head
*
Loose
spark plug
• Worn,
stuck or broken piston
rings
•
Worn
or
damaged cylinder
and piston
ft
Excessive
noise
•
Incorrect valve shim adjustment (page
3-5)
•
Sticking valve
or
broken
valve spring
•
Damaged or worn
camshaft
•
Damaged camshaft drive
gear
ft
Abnormal noise (piston)
•
Worn cylinder
and
piston
*
Worn piston pin
or
piston pin hole
•
Worn
connecting rod big
end
bearing
Compression
too
high
•
Excessive carbon
build-up
on
piston
top
or
combustion
chamber
ft
8-1
Hide quick links:
Advertisement
