ENGINE
4-21
NOTE: Be sure to measure each guide and valve
combination individually.
8. Replace valve and/or guide if clearance is excessive.
NOTE: If valve guides are replaced, valve seats must
be reconditioned. Refer to Valve Seat Reconditioning
for procedure.
VALVE SEAT RECONDITIONING
Valve Seat Inspection
Inspect valve seat in cylinder head for pitting, burnt spots,
roughness, and uneven surface. If any of the above conditions
exist, the valve seat must be reconditioned. If the valve seat is
cracked the cylinder head must be replaced.
Cylinder Head Reconditioning
NOTE: Servicing the valve guides and valve seats
requires special tools and a thorough knowledge of
reconditioning techniques. Follow the instructions
provided in the Valve Seat Reconditioning Kit.
Wear eye protection when performing cylinder head
service. Valve guide replacement will require heating
of the cylinder head. Wear gloves to prevent burns.
Follow the manufacturers instructions provided with the valve
seat cutters in the Valve Seat Reconditioning Kit. Abrasive
stone seat reconditioning equipment can also be used. Keep
valves in order with their respective seat.
NOTE: Valve seat width and point of contact on the
valve face is very important for proper sealing. The
valve must contact the valve seat over the entire
circumference of the seat, and the seat must be the
proper width all the way around. If the seat is uneven,
compression leakage will result. If the seat is too
wide, seat pressure is reduced, causing carbon
accumulation and possible compression loss. If the
seat is too narrow, heat transfer from valve to seat is
reduced and the valve may overheat and warp,
resulting in burnt valves.
1. Install pilot into valve guide.
2. Apply cutting oil to valve seat and cutter.
3. Place 46
∘
cutter on the pilot and make a light cut.
4. Inspect the cut area of the seat. If the area is less than 75%
of the circumference of the seat, rotate the pilot 180
∘
and
make another light cut.
If the cutter now contacts the uncut portion of the seat, check
the pilot. Look for burrs, nicks, or run out. If the pilot is bent it
must be replaced.
Summary of Contents for AT56-69E
Page 35: ...MAINTENANCE 2 25 ...
Page 45: ...CVT SYSTEM 3 4 CVT EXPLODED VIEW ...
Page 56: ...ENGINE 4 3 ENGINE ILLUSTRATION ENGINE EXPLODED VIEW ...
Page 57: ...ENGINE 4 4 ...
Page 58: ...ENGINE 4 5 COOLING SYSTEM EXPLODED VIEW ...
Page 59: ...ENGINE 4 6 OIL FLOW DIAGRAM ...
Page 125: ...FUEL AND CARBURETOR 6 15 FUEL TANK SYSTEM ...
Page 135: ...BODY SUSPENSION STEERING 7 6 SUSPENSION ...
Page 142: ...BODY SUSPENSION STEERING 7 13 STEERING ...
Page 151: ...BRAKES 8 6 FRONT BRAKE EXPLODED VIEW MASTER CYLINDER ...
Page 196: ...ELECTRICAL 9 31 WIRE DIAGRAM ...