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Disassembly/Inspection and Service
KohlerEngines.com
32 690 01 Rev. D
Disassemble Cylinder Heads
NOTE: On engines with valve stem seals on intake
valves; use a new seal whenever valve is
removed or if seal is deteriorated or damaged.
Never reuse an old seal.
1. Remove adjusters, pivots, rocker arms, studs, and
guide plate with adjusters from cylinder head.
2. Compress valve springs using a valve spring
compressor.
3. Once valve spring is compressed, remove following
items.
● Valve spring keepers.
● Valve spring retainers.
● Valve springs.
● Valve spring caps.
● Intake and exhaust valves (mark position).
● Valve stem seal (intake valve some models).
4. Repeat above procedure for other cylinder head. Do
not interchange parts from 1 cylinder head to
another.
Inspection and Service
Valve Details
H
E
F
A
C
D
F
E
G
A
H
D
A
B
B
G
Intake Valve
Exhaust Valve
Intake Insert
Exhaust Insert
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 flatness of cylinder head and corresponding top surface of crankcase, using a surface plate or
piece of glass and feeler gauge. Maximum allowable out of flatness 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. See valve details and specifications.
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 first. After removal, clean valve
heads, faces, and stems with a power wire brush. Then, carefully inspect each valve for defects such as warped
head, excessive corrosion, or worn stem end. Replace valves found to be in bad condition.
