Kohler Command PRO ECH630 Service Manual page 116

Section 9
Inspection and Reconditioning
Use the following procedure to accurately measure
the piston-to-bore clearance:
1. Use a micrometer and measure the diameter of
the piston 6 mm (0.24 in.) above the bott om of the
piston skirt and perpendicular to the piston pin.
See Figure 9-4.
Measure 6 mm above the
Bottom of Piston Skirt at
Right Angles to Piston Pin
Figure 9-4. Measuring Piston Diameter.
2. Use an inside micrometer, telescoping gauge, or
bore gauge and measure the cylinder bore. Take
the measurement approximately 63.5 mm
(2.5 in.) below the top of the bore and
perpendicular to the piston pin.
3. Piston-to-bore clearance is the diff erence between
the bore diameter and the piston diameter (Step 2
minus Step 1).
Flywheel
Inspection
Inspect the fl ywheel for cracks and the fl ywheel
keyway for damage. Replace the fl ywheel if it is
cracked. Replace the fl ywheel, the crankshaft , and
the key if fl ywheel key is sheared or the keyway is
damaged.
Inspect the ring gear for cracks or damage. Kohler
does not provide the ring gear as a serviceable part.
Replace the fl ywheel if the ring gear is damaged.
9.4
Cylinder Head and Valves
Inspection and Service
Aft er cleaning, check the fl atness of the cylinder head
and the corresponding top surface of the crankcase,
using a surface plate or piece of glass and feeler gauge
as shown in Figure 9-5. The maximum allowable out
of fl atness is 0.076 mm (0.003 in.).
6 mm (0.24 in.)
Figure 9-5. Checking Cylinder Head Flatness.
Carefully inspect the valve mechanism parts. Inspect
the valve springs and related hardware for excessive
wear or distortion. Check the valves and valve seat
area or inserts for evidence of deep pitt ing, cracks,
or distortion. Check clearance of the valve stems
in the guides. See Figure 9-6 for valve details and
specifi cations.