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Remove all carbon from valves.
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Inspect each valve for wear, burn or distortion at its face and stem end, as necessary, replace it.
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Measure length “a” of valve.
If measured length is out of specification, replace valve.
Valve length “a”
In: 100.73 – 101.17 mm (3.9658 – 3.9830 in.)
Ex: 100.53 – 100.97 mm (3.9579 – 3.9751 in.)
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Measure diameter “b” of valve.
If measured diameter is out of specification, replace valve.
Valve head diameter “b”
In: 33.38 – 33.62 mm (1.3142 – 1.3236 in.)
Ex: 28.88 – 29.12 mm (1.1370 – 1.1464 in.)
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Valve seat repair:
A valve seat not producing a uniform contact with its valve or showing width of seating contact that is out of specified range must be repaired by regrinding or by cutting and regrinding and finished by lapping.
a.
Valve Seat:
Use valve seat cutters (1) to make a cut as illustrated in the figure.
Seat width
“a”: 1.8 mm (0.071 in.)
b.
Valve Lapping:
Lap valve on seat in two steps, first with coarse size lapping compound applied to face and the second with fine-size compound, each time using valve lapper according to usual lapping method.