TOHATSU 40 Service Manual page 104

SECTION 4
4. Wipe off all traces of oil and thoroughly wash the cylinder
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block and crankcase with warm, soapy water. Air dry the
cylinder block and crankcase. Dry all holes and passages with low
pressure compressed air.
5. Coat the cylinder walls with genuine engine oil or certified
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TC-W3 oil to protect them from corrosion.
Inspection
Before inspection of the powerhead, all components
must be perfectly clean and free of contaminants.
If it is determined after complete inspection that
cylinder resurfacing or boring is necessary, all
operations must be performed at a qualified
machine shop. Light scuffing or burn does not
require boring for removal. Use water-resistant
sand paper of around #320 to remove the
damages, and then use #400 and #600 to finish.
1. Visually inspect all internal components. Inspect for unusual wear
patterns, heat-related discoloration of bearings, broken parts, and
scuffing or damage to aluminum parts.
2. Inspect the intake manifold and reed valves. See Intake Manifold
in Section 3.
3. Check the cylinder head for warpage using a machinist
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straight edge and the thickness gauge set (Part No. 353-
72251-0). If warpage exceeds 0.004 in [0.10 mm], replace the
cylinder head.
4. Using an accurate dial indicator, measure the crankshaft
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deflection with the upper and lower main bearings installed.
Measure as follows:
• Support both ends of the crankshaft in precision V-blocks or an
alignment jig.
• Slowly rotate crankshaft and record measurement at each
crankshaft bearing (1) and at both ends of the crankshaft.
If deflection is more than 0.002 in [0.05 mm] on either end, replace
the crankshaft.
4-30
NOTE
CAUTION
T1225
T1226
T1227
T1228
3-/ 4-Cylinder