Kohler Command CH620 Service Manual page 91

cylinder reconditioning is necessary. Once removed,
they must be replaced.
2. Mark position of push rods as either intake or
exhaust and cylinder 1 or 2. Push rods should
always be reinstalled in same positions.
3. Carefully remove push rods, cylinder heads and
head gaskets.
4. Remove lifters from lifter bores. Use a Hydraulic
Lifter Tool. Do not use a magnet to remove lifters.
Mark lifters by location, as either intake or exhaust
and cylinder 1 or 2. Hydraulic lifters should always
be reinstalled in same position.
Disassemble Cylinder Heads
NOTE: These engines use valve stem seals on intake
valves. Use a new seal whenever valve is
removed or if seal is deteriorated in any way.
Never reuse an old seal.
Inspection and Service
Valve Details
EXHAUST VALVE
E
G
H
Dimension
A Seat Angle
B Insert O.D.
C Guide Depth
D Guide I.D.
E Valve Head Diameter
F Valve Face Angle
G Valve Margin (Min.)
H Valve Stem Diameter
24 690 06 Rev. O
F
C
D
D
Intake
89°
36.987/37.013 mm (1.4562/1.4572 in.)
4 mm (0.1575 in.)
7.038/7.058 mm (0.2771/0.2779 in.)
33.37/33.63 mm (1.3138/1.3240 in.)
45°
1.5 mm (0.0591 in.)
6.982/7.000 mm (0.2749/0.2756 in.)
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Disassembly/Inspection and Service
1. Remove screws, rocker arm pivots and rocker arms
from cylinder head. Note screw color for reassembly.
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 seals (intake valve only).
4. Repeat above procedure for other cylinder head. Do
not interchange parts from one cylinder head to
other.
B
A
EXHAUST
INSERT
INTAKE
INSERT
A
B
32.987/33.013 mm (1.2987/1.2997 in.)
7.038/7.058 mm (0.2771/0.2779 in.)
29.37/29.63 mm (1.1563/1.1665 in.)
6.970/6.988 mm (0.2744/0.2751 in.)
INTAKE VALVE
F
E
G
H
Exhaust
89°
6.5 mm (0.2559 in.)
45°
1.5 mm (0.0591 in.)
91