Evinrude E-tec 75 HP, Service Manual

Page: 214 / 344

214
POWERHEAD
INSPECTION
Crankshaft
Measure the diameter of each crankpin and main
bearing journal. The lower main bearing journal
would only be measured if the bearing was
removed for another reason.
Cylinder Bore
Use Cylinder Bore Gauge, P/N 771310, to inspect
each cylinder bore for an out-of-round, oversize,
or tapered condition. Be sure the gauge is per-
fectly square in the bore when measuring.
Measure each cylinder in at least two areas. Each
area should be measured twice. The difference
between the two measurements in each area is
the cylinder out-of-round dimension.
•
The cylinder must not be out-of-round by more
than 0.004 in. (0.10 mm).
The dimensional difference between the two
areas is cylinder taper.
•
The cylinder taper must not exceed 0.002 in.
(0.05 mm).
The difference between the measurements and
standard bore is cylinder oversize. For dimen-
sions, refer to
TECHNICAL DATA on p. 18.
•
The cylinder must not be oversized by more
than 0.003 in. (0.08 mm).
IMPORTANT:
If any cylinder is outside these
tolerances, it must be bored oversize. It is permis-
sible to have one or more oversize pistons in an
engine.
Pistons
Visually inspect pistons for signs of abnormal
wear, scuffing, cracks, or burning.
Piston Rings
For new ring sets, place each ring separately in its
respective bore. Use a piston to square the ring in
002142
TYPICAL 46528
1. Measurement areas
DR3482
1