Mercury 100 FourStroke, Service Manual

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5B-10 - MID-SECTION 90-830234R3 DECEMBER 1997
Power Trim Partial Leak Down at
Maximum Trim
Power Trim Date Code 14182 and Below – Service
Bulletin No. 94-13.
Some units, when trimmed to the maximum 20 de-
gree limit, will leak down approximately 5 degrees
and then hold. The leak will ONLY occur while the
boat is under power. The cause for the 5 degree leak
down is the lack of a fluid passage between the shock
piston and the memory piston.
1. Disassemble the tilt ram assembly and remove
the memory piston.
2. Cut a small groove 0.020 - 0.040 in. (0.5 - 1.0mm)
deep across the top face of the memory piston.
The groove will allow oil passage when the shock
piston and memory piston are in contact. The
groove can be made with a hacksaw or triangular
file.
NOTE: Power trim assemblies with Date Code
14183 and ABOVE have a groove in the shock piston
to allow fluid passage. The memory piston remains
the same and does not have a groove across the
face.
3. Remove all burrs and filings from the memory
piston.
4. Reassemble the trim/tilt ram assembly using new
O-rings and seals.
a
b
c
a - Shock Piston
b - Memory Piston
c - 0.020 – 0.040 in. (0.5 – 1.0mm) Groove