Service Manual

5-14 ENGINE TOP END
Valves
Valve Clearance Inspection
•
Refer to the Valve Clearance Inspection in the Periodic
Maintenance chapter.
Valve Clearance Adjustment
•
Refer to the Valve Clearance Adjustment in the Periodic
Maintenance chapter.
Valve Seat Inspection
•
Refer to the Valve Seat Inspection in the Periodic Mainte-
nance chapter.
Valve Seat Repair
•
Refer to the Valve Seat Repair in the Periodic Mainte-
nance chapter.
Valve Head Thickness
•
Remove the valve (see Valve Mechanism Removal/Instal-
lation).
•
Measure the v
alve head thickness.
If the valve head thickness (valve margin) [A] is less than
the service limit, replace the valve with a new one.
Valve Head Thickness
Service Limit:
Inlet, Exh
aust
0.3 mm (0.012 in)
Valve Stem Runout
•
Support the valve on V blocks at each end of the stem.
•
Position a dial gauge perpendicular to the stem.
•
Turn the valve and read the variation on the dial gauge.
If the stem runout is greater than service limit, replace the
valve.
Valve Stem Runout
Service Limit:
Inlet, Exhaust
TIR 0.05 mm (0.002 in.)
Valve Stem Diameter
•
Measure the diameter of the valve stem [A] in two di-
rections at right angles, at four different positions on the
stem.
If any single measurement is less than the service limit,
replace the valve with a new one.
Valve Stem Diameter
Service Limit:
Inlet 5.95 mm (0.234 in.)
Exhaust 5.93 mm (0.233 in.)