INSPECTION


CYLINDER HEAD
1.Check the cylinder head for water leakage, gas leakage, damage or cracks before cleaning.
2.Completely remove oil, scale, sealants, carbon, etc. After cleaning oil passages, blow air to make sure that they are not clogged.

3.Check the cylinder head gasket surface for flatness by using a straightedge in the directions of illustration.
Limit value: 0.03 mm

VALVE

1.Repair the valve seat if the contact with the valve seat is poor, uneven or broken.
2.Measure the margin.
If the limit is exceeded, replace the valve.
Standard value:
    Inlet 1.3 mm
    Exhaust 1.5 mm
Limit value:
    Inlet 0.8 mm
    Exhaust 1.0 mm

3.Measure overall length of the valve.
If the limit is exceeded, replace the valve.
Standard value:
    Inlet 121.64 mm
    Exhaust 112.95 mm
Limit value:
    Inlet 121.14 mm
    Exhaust 112.45 mm

VALVE SPRING

1.Measure free height of the spring.
If the limit is exceeded, replace the spring.
Standard value:
    Inlet side: 65.7 mm
    Exhaust side: 64.2 mm
Limit value:
    Inlet side: 65.2 mm
    Exhaust side: 63.7 mm
2.Measure squareness of the spring.
If the inclination exceeds the limit, replace the spring.
Standard value: 2° max.
Limit value: 4°

VALVE GUIDE

Measure clearance between the valve guide and valve stem. If the clearance exceeds the limit, replace the valve guide or valve, or both.
Standard value:
    Inlet 0.020 - 0.047 mm
    Exhaust 0.035 - 0.062 mm
Limit value:
    Inlet 0.10 mm
    Exhaust 0.15 mm

VALVE SEAT

Assemble the valve, then measure the contact width. If the measurement exceeds the specified limit, replace or correct the valve seat.
Standard value: 1.1 - 1.5 mm
caution If the variation in the width exceeds 0.2 mm even if the contact width is within the standard value, replace or correct the valve sheet.

REPAIR PROCEDURE OF VALVE SEAT
1.Check clearance between valve guide and valve and replace the valve guide if necessary before repairing the valve seat.

2.Repair the valve seat so that seat width and seat angle can become the specified shape.
3.Smear a lapping compound on the valve and valve seat after the repair. Fit the valve into the valve seat.

REPLACEMENT PROCEDURE OF VALVE SEAT

1.Scrape the valve seat to be replaced from inside. Make its wall thickness thin before pulling out.

2.Repair the valve seat hole of the cylinder head to match it with the diameter of the press fit oversize valve seat.
Inlet valve seat bore diameter:
    0.3 O.S.: 31.80 - 31.82 mm
Exhaust valve seat bore diameter:
    0.3 O.S.: 27.80 - 27.82 mm
3.Press fit the valve seat, paying attention not to score the cylinder head inner diameter at room temperature.
4.Ream the valve seat.
Refer to “Repair procedures of valve seat."

REPLACEMENT PROCEDURE OF VALVE GUIDE
1.Pull out the valve guide with a press toward the cylinder block side.
2.Ream the valve guide hole of the cylinder head to match it with the press fit oversize valve guide.
caution Do not use a valve guide with the same size as the pulled out valve guide because it cannot be press fitted.
Valve guide bore diameter
    0.05 O.S.: 11.05 - 11.07 mm

3.Press fit the valve guide to the illustrated dimension.
Standard value: 17.1 - 17.7 mm
note Press fit the valve guide from the cylinder head top surface.
4.After pressing fit the valve guide, insert a new valve to check for sliding.