Service Manual

ENGINE TOP EN D 5-11
Valves
Valve Clearance Inspection
Refer to Valve Clearance Inspection in the Periodic Main-
tenance Chapter (2nd chapter).
Va lve Clearance Adjustment
Refer to Valve Clearance Adjustment in the Periodic
Maintenance Chapter (2nd chapter).
Valve Seat Inspection
Refer t o Valve S eat Inspection in the Periodic Mainte-
nance Chapter (2nd chapter).
Valve Seat Repair
Refer to Valve Seat Repair in the Periodic Maintenance
Chapter (2nd chapter).
ValveHeadThickness
•
Remove the valve (see Valve Mechanism Removal/Instal-
lation).
•
Measure the thickness of the valve head.
If the valve head thickness (valve margin) [A] is less than
the service limit, replace the valve.
Valve Head Thickness
Service Limit
IN:
0.35 mm (0.014 in.)
EX:
0.36 mm (0.014 in.)
Valve Stem Runout
•
Support the valve in 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 R unout
Service Limit (IN, EX): 0.05 mm (0.002 in.)
Va lve 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.
Valve Stem Diameter
Service Limit (IN, EX): 5.93 mm (0.233 in.)