Mercury 100 FourStroke, Service Manual

Page: 252 / 574

4-40 - POWERHEAD 90-830234R3 DECEMBER 1997
•
Some models may be equipped with the following
sleeve , which retains an O-ring seal . The sleeve
is pushed over the crankshaft end until it bottoms-
out on a crank flange, leaving space for the O-ring
between the sleeve lip and the end of the crank-
shaft. Pop out the O-ring with an awl - replace the
O-ring seal.
IMPORTANT: The End Cap (lower) inside seal
rides on the “wear sleeve” . If the outer surface of
the sleeve is grooved or corroded/pitted, replace
by pulling off the sleeve with pliers--it may be
necessary to heat the sleeve to release the Loc-
tite sealant. Replace O-ring AFTER wear-sleeve
is installed on crankshaft.
•
To install the sleeve, apply Loctite 271 to the
crankshaft; align sleeve squarely with crank-
shaft, place a block of wood over end of sleeve,
and tap lightly until it bottoms-out. Wipe off ex-
cess sealant. The sleeve is lightweight
(31-gauge) stainless steel - DO NOT collapse the
end contour or otherwise distort its shape.
a
b
c
a - Wear Sleeve Surface
b - Carrier
c - O-ring
Cleaning and Inspection
Cylinder Block and Crankcase Cover
IMPORTANT: Crankcase cover and cylinder
block are a matched, line-bored assembly and
never should be mismatched by using a different
crankcase cover or cylinder block.
•
Inspect cylinder block and crankcase cover for
cracks or fractures.
•
Check gasket surfaces for nicks, deep grooves,
cracks and distortions that could cause compres-
sion leakages.
•
Check that all water passages in cylinder block
are not obstructed. Check locating pins in cylin-
der block that they are tight.
•
Check crankcase cover fuel/bleed passages that
they are not obstructed. Verify that check valves
in crankcase cover are not damaged.
•
Thoroughly clean cylinder block and crankcase
cover. Verify that all sealant and old gaskets are
removed from matching surfaces. Clean all car-
bon deposits from exhaust ports.
•
Inspect spark plug holes for stripped or damaged
threads.
If crankcase cover and cylinder block is to be
submerged in a very strong cleaning solution, it
will be necessary to remove the crankcase cover/
cylinder block bleed system from cover/cylinder
block to prevent damage to hoses and check
valves.