S-51
WG972-E2, DF972-E2, WSM
GASOLINE / LPG ENGINE
Valve Recessing
1. Clean the cylinder head, the valve face and seat.
2. Insert the valve into the valve guide.
3. Measure the valve recessing with a depth gauge.
4. If the measurement exceeds the allowable limit, replace the
valve.
5. If it still exceeds the allowable limit after replacing the valve,
replace the cylinder head.
W1061543
Clearance between Valve Stem and Valve Guide
1. Remove carbon from the valve guide section.
2. Measure the valve stem O.D. with an outside micrometer.
3. Measure the valve guide I.D. with a small hole gauge, and
calculate the clearance.
4. If the clearance exceeds the allowable limit, replace the valves.
If it still exceeds the allowable limit, replace the valve guide.
W10311740
Valve recessing (Intake
and Exhaust)
Factory spec.
0.10 (protrusion) to
0.10 (recessing) mm
0.0039 (protrusion) to
0.0039 (recessing) in.
Allowable limit
0.30 (recessing) mm
0.0118 (recessing) in.
(1) Cylinder Head Surface (A) Recessing
(B) Protrusion
Clearance between
valve stem and valve
guide
Factory spec.
0.030 to 0.057 mm
0.00118 to 0.00224 in.
Allowable limit
0.10 mm
0.0039 in.
Valve stem O.D. Fac tory spec.
5.968 to 5.980 mm
0.23496 to 0.23543 in.
Valve guide I.D. Factory spec.
6.010 to 6.025 mm
0.23661 to 0.23720 in.