INSPECTION


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

caution The grinding limit shall be within 0.2 mm in combination with the cylinder block to be assembled.
3.For the flatness on the cylinder head bottom, measure distortion using a straight edge and free gauge. If the distortion exceeds the limit, grind and repair it.
Distortion on bottom
    Standard value: Within 0.05 mm
    Limit: 0.02 mm
    Grinding limit: 0.2 mm
Cylinder head height: 128.5 mm

VALVE

1.Repair the valve seat if contact with the valve seat is poor, uneven or broken.
2.Measure the margin.
If the limit is exceeded, replace the valve.
Standard value:
    Intake 1.022 mm
    Exhaust 1.094 mm
Limit:
    Intake 0.522 mm
    Exhaust 0.594 mm

3.Measure overall length of the valve.
If the limit is exceeded, replace the valve.
Standard value:
    Intake 113.18 mm
    Exhaust 105.89 mm
Limit:
    Intake 112.68 mm
    Exhaust 105.39 mm

VALVE SPRING

1.Measure free height of the spring.
If the limit is exceeded, replace the spring.
Standard value: 48.12 mm
Limit: 47.12 mm
2.Measure squareness of the spring.
If the inclination exceeds the limit, replace the spring.
Standard value: 2° or less
Limit: 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:
    Intake 0.020 - 0.047 mm
    Exhaust 0.030 - 0.054 mm
Limit:
    Intake 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 the valve seat.
Standard value
    Intake: 1.16 - 1.46 mm
    Exhaust: 1.35 - 1.65 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 are to the specified shape.
3.Lap valve and valve seat with lapping compound after repairing valve seat.

REPLACEMENT PROCEDURE OF VALVE SEAT

1.Scrape the valve seat to be replaced from inside to 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 oversize valve seat to be press fitted.
Intake valve seat bore diameter:
    0.3 O.S.: 36.22 - 36.24 mm
Exhaust valve seat bore diameter:
    0.3 O.S.: 30.22 - 30.24 mm
3.Press fit the valve seat, taking care not to score the cylinder head bore at room temperature.
4.Ream the valve seat.
Refer to "Repair procedure 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 diameter of the oversize valve guide to be press fitted.
caution Do not use a valve guide with the same size as that of the pulled out valve guide because it cannot be press fitted.
Valve guide bore diameter
    0.25 O.S.: 11.23 - 11.25 mm

3.Press fit the valve guide to the illustrated dimension.
Standard value: 14.6 - 15.2 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.