Kohler MAGNUM M18

M18 & M20
SECTION 10
INSPECTION AND RECONDITIONING
Clean all parts thoroughly. Only clean parts can be
accurately inspected and gauged for wear or damage.
There are many commercially available cleaners that
quickly remove grease, oil and grime accumulation
from engine parts. When such a cleaner is used, fo/-
low the manufacturers instructions and safety precau-
tions carefully. Use gasket remover or paint remover
to remove RTV from crankcase and closure plate. Do
not scrape the surfaces when cleaning as this will
damage the surfaces. This could result in leaks.
Make sure that all of the cleaner is removed before the
engine is reassembled and placed in operation. Even
small amounts of these cleaners quickly break down
the lubricating properties of engine oil.
Refer to A Guide to Engine Rebuilding (TP-2150) for
additional information. Measurement Guide
(TP-2158-A) and Engine Inspection Data Record
(TP-2435) are also available; use these to record in-
spection results.
FLYWHEEL
Inspection
Inspect the flywheel for cracks, and the flywheel
keyway for damage. Replace flywheel if cracked.
Replace the flywheel, the crankshaft, and the key if
flywheel key is sheared or the keyway damaged.
Inspect ring gear for cracks or damage. Kohler no
longer provides ring gears as a serviceable part. Re-
Place flywheel if the ring gear is damaged.
CYLINDER HEADS
Inspection
Blocked cooling fins often cause localized “hot spots"
which can result in “blown” cylinder head gaskets. If
gasket fails in area surrounding one of the retaining
capscrews, high temperature gases can bum away
portions of the aluminum alloy head. A cylinder head
in this condition must be replaced. It will also be nec-
essary to replace the head screws. The high tempera-
tures that caused the “blown” gasket could have
made the screws ductile which will cause them to
stretch when tightened.
If the cylinder heads appear in good condition, use a
block of wood or plastic scraper to scrape away car-
bon deposits. Be careful not to nick or scratch the
aluminum, especially in gasket seating area.
Cylinder heads should also be checked for flatness,
Use a feeler gauge and a surface plate or piece of
plate glass to make this check. Cylinder head flat-
ness should not vary more than .003”; if it does, re-
place the cylinder head (see Figure 10-1).
NOTE: Measure cylinder head flatness between each
cap screw hole.
Apply Slight
Downward
Pressure
Figure 10-1. Checking Cylinder Head Flatness.