CYLINDER HEAD — Inspection (Cont'd) / Valve Dimensions / Valve Spring

EM-34prose procedure

Inspection (Cont'd)

Replacing valve seat for service parts (continued)

3
Heat cylinder head to 110 to 120°C (230 to 248°F).
SEM008A
4
Press fit valve seat until it seats on the bottom.
5
Cut or grind valve seat using suitable tool at the specified dimensions as shown in S.D.S.
6
After cutting, lap valve seat with abrasive compound.
7
Check valve seating condition. Seat face angle "α": 45°15′ - 45°45′ deg. Contacting width "W": Intake 1.34 - 1.63 mm (0.0528 - 0.0642 in); Exhaust 1.70 - 2.12 mm (0.0669 - 0.0835 in).
SEM892B

Specification	Value
Seat face angle αBoth intake and exhaust	45°15′ - 45°45′deg
Contacting width W — IntakeAfter cutting/lapping	1.34 - 1.63 (0.0528 - 0.0642)mm (in)
Contacting width W — ExhaustAfter cutting/lapping	1.70 - 2.12 (0.0669 - 0.0835)mm (in)

Seat face angle αBoth intake and exhaust

45°15′ - 45°45′deg

Contacting width W — IntakeAfter cutting/lapping

1.34 - 1.63 (0.0528 - 0.0642)mm (in)

Contacting width W — ExhaustAfter cutting/lapping

1.70 - 2.12 (0.0669 - 0.0835)mm (in)

VALVE DIMENSIONS

Check dimensions in each valve. For dimensions, refer to S.D.S. When valve head has been worn down to 0.5 mm (0.020 in) in margin thickness, replace valve.

IMPORTANT

Grinding allowance for valve stem tip is 0.2 mm (0.008 in) or less.

Specification	Value
Valve head margin thickness — Replace atWear limit; replace valve if worn below	0.5 (0.020)mm (in)
Grinding allowance for valve stem tipMaximum	0.2 (0.008) or lessmm (in)

Valve head margin thickness — Replace atWear limit; replace valve if worn below

0.5 (0.020)mm (in)

Grinding allowance for valve stem tipMaximum

0.2 (0.008) or lessmm (in)

VALVE SPRING

Squareness

Valve spring squareness

1
Measure "S" dimension. Out-of-square: Less than 1.74 mm (0.0685 in).
SEM288A
2
If it exceeds the limit, replace spring.

Specification	Value
Valve spring out-of-square S — LimitReplace if exceeds	Less than 1.74 (0.0685)mm (in)

Valve spring out-of-square S — LimitReplace if exceeds

Less than 1.74 (0.0685)mm (in)

Pressure

Check valve spring pressure. If it is less than the limit, replace spring.

Specification	Value
Valve spring pressure — StandardStandard	369.7 (37.7, 83.1) at 23.64 (0.9307)N (kg, lb) at height mm (in)
Valve spring pressure — LimitReplace if less	More than 330.516 (33.702, 74.313) at 23.64 (0.9307)N (kg, lb) at height mm (in)

Valve spring pressure — StandardStandard

369.7 (37.7, 83.1) at 23.64 (0.9307)N (kg, lb) at height mm (in)

Valve spring pressure — LimitReplace if less

More than 330.516 (33.702, 74.313) at 23.64 (0.9307)N (kg, lb) at height mm (in)

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