78
Disassembly/Inspection and Service
KohlerEngines.com
66 690 14 Rev. A
Inspection and Service
Valve Details
EXHAUST VALVE
INTAKE VALVE
EXHAUST
INSERT
INTAKE
INSERT
H
H
G
G
E
E
F
F
A
A
C
D
D
B
B
Dimension
Intake
Exhaust
A
Seat Angle
89°
89°
B
Insert O.D.
36.987/37.013 mm (1.4562/1.4572 in.)
32.987/33.013 mm (1.2987/1.2997 in.)
C
Guide Depth
4 mm (0.1575 in.)
6.5 mm (0.2559 in.)
D
Guide I.D.
7.038/7.058 mm (0.2771/0.2779 in.)
7.038/7.058 mm (0.2771/0.2779 in.)
E
Valve Head Diameter
33.37/33.63 mm (1.3138/1.3240 in.)
29.37/29.63 mm (1.1563/1.1665 in.)
F
Valve Face Angle
45°
45°
G
Valve Margin (Min.)
1.5 mm (0.0591 in.)
1.5 mm (0.0591 in.)
H
Valve Stem Diameter
6.982/7.000 mm (0.2749/0.2756 in.)
6.970/6.988 mm (0.2744/0.2751 in.)
After cleaning, check
fl
atness of cylinder head and corresponding top surface of crankcase, using a surface plate or
piece of glass and feeler gauge. Maximum allowable out of
fl
atness is 0.076 mm (0.003 in.).
Carefully inspect valve mechanism parts. Inspect valve springs and related hardware for excessive wear or distortion.
Check valves and valve seat area or inserts for evidence of deep pitting, cracks, or distortion. Check clearance of
valve stems in guides.
Hard starting or loss of power accompanied by high fuel consumption may be symptoms of faulty valves. Although
these symptoms could also be attributed to worn rings, remove and check valves
fi
rst. After removal, clean valve
heads, faces, and stems with a power wire brush.
Then, carefully inspect each valve for defects such as a warped head, excessive corrosion, or a worn stem end.
Replace valves found to be in bad condition.
