CYLINDER HEAD

EM-44prose 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.
SEM892B
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).

Specification	Value
Valve seat face angle "α"	45°15' - 45°45'deg
Valve seat contacting width "W" - Intake0.0528 - 0.0642 in	1.34 - 1.63mm
Valve seat contacting width "W" - Exhaust0.0669 - 0.0835 in	1.70 - 2.12mm

Valve seat face angle "α"

45°15' - 45°45'deg

Valve seat contacting width "W" - Intake0.0528 - 0.0642 in

1.34 - 1.63mm

Valve seat contacting width "W" - Exhaust0.0669 - 0.0835 in

1.70 - 2.12mm

VALVE DIMENSIONS

Check dimensions in each valve. For dimensions, refer to S.D.S.

NOTE

When valve head has been worn down to 0.5 mm (0.020 in) in margin thickness, replace valve. Grinding allowance for valve stem tip is 0.2 mm (0.008 in) or less.

VALVE SPRING

Squareness

1
Measure "S" dimension. Out-of-square: Less than 1.80 mm (0.0709 in).
SEM288A
2
If it exceeds the limit, replace spring.

Specification	Value
Valve spring out-of-square "S"0.0709 in	Less than 1.80mm

Valve spring out-of-square "S"0.0709 in

Less than 1.80mm

Pressure

Check valve spring pressure.

Specification	Value
Valve spring pressure - Standardat 25.26 mm (0.9945 in)	344.42 (35.12, 77.44)N (kg, lb)
Valve spring pressure - Limitat 25.26 mm (0.9945 in)	More than 323.73 (33.01, 72.79)N (kg, lb)

Valve spring pressure - Standardat 25.26 mm (0.9945 in)

344.42 (35.12, 77.44)N (kg, lb)

Valve spring pressure - Limitat 25.26 mm (0.9945 in)

More than 323.73 (33.01, 72.79)N (kg, lb)

If it exceeds the limit, replace spring.

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