INSPECTION


CYLINDER HEAD
1.Before cleaning, check the cylinder head for leakage of coolant or exhaust gas as well as cracks or other damage.
2.Remove oil, scale, sealant, carbon and other residues completely. Clean the oil passages and blow compressed air through them to verify that they are free of restriction.

3.
caution The grinding limit for the cylinder head and block combined is 0.2 mm.
Using a straight edge and a thickness gauge, measure the flatness of the cylinder head bottom surface.
Bottom face distortion
    Standard value: 0.03 mm or less
Cylinder head height (standard value for new part): 112.9 - 113.1 mm

VALVE

1.If the valve face-to-seat contact is uneven or interrupted, correct the valve seat.
2.Measure the valve head margin. If the measured value exceeds the limit, replace with a new valve.
Standard value:
    Inlet 0.85 mm
    Exhaust 1.50 mm

3.Measure the valve overall length. If the measured value exceeds the limit, replace with a new valve.
Standard value:
    Inlet 87.21 mm
    Exhaust 88.54 mm
Limit:
    Inlet 86.71 mm
    Exhaust 88.04 mm

VALVE SPRING

1.Measure the valve spring free height. If the measured value exceeds the limit, replace with a new spring.
Standard value: 49.6 mm
Limit: 48.6 mm
2.Measure the valve spring out-of-squareness. If the measured value exceeds the limit, replace with a new spring.
Standard value: 2° or less
Limit: 4°

VALVE GUIDE

Measure the clearance between the valve guide and the valve stem. If the measured value exceeds the limit, replace the valve guide or the valve, or both.
Standard value:
    Inlet 0.020 - 0.047 mm
    Exhaust 0.030 - 0.057 mm
Limit:
    Inlet 0.10 mm
    Exhaust 0.15 mm

VALVE SEAT
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.

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

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
    0.30 O.S.: 31.83 - 31.85 mm
Exhaust valve seat bore diameter
    0.30 O.S.: 28.32 - 28.34 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.
caution Do not use a valve guide with the same size as the pulled out valve guide because it cannot be press fitted.
Ream the valve guide hole of the cylinder head to match it with the press fit oversize valve guide.
Inlet valve guide bore diameter
    0.05 O.S.: 10.56 - 10.58 mm
Exhaust valve guide bore diameter
    0.05 O.S.: 10.55 - 10.57 mm

3.Press fit the valve guide to the illustrated dimension.
Standard value: 12.7 - 13.3 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.