Powerhead Cleaning And Inspection; Cylinder Block And Crankcase Cover - Mercury 15XD Service Manual

POWERHEAD

Powerhead Cleaning and Inspection

Cylinder Block and Crankcase Cover

IMPORTANT: Crankcase cover and cylinder block are a matched, line-bored as-
sembly and must be replaced as a set.
1. Thoroughly clean cylinder block and crankcase cover with Quicksilver Power Tune
Engine Cleaner (91-92-15104A12). Verify that all sealant and old gaskets are re-
moved from mating surfaces. Remove all carbon deposits from exhaust ports, de-
compression ports and cylinder dome.
2. Inspect cylinder block and crankcase cover for cracks or fractures.
3. Check gasket surfaces for nicks, deep grooves, cracks and distortion.
4. Inspect all water and fuel passages in cylinder block and crankcase cover for obstruc-
tions.
5. Verify that all fittings and plugs are tight. If the center main bearing alignment pin is
loose, cylinder block and crankcase cover must be replaced.
a -
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a
Alignment Pin
57125
90-826883R2 JUNE 1998