Mercury 225 EFI Service Manual page 376

POWERHEAD
4. Check piston rings to be sure that they fit freely in ring groove.
5. Lubricate piston, rings and cylinder wall with 2-Cycle Outboard Oil.
6. Rotate each piston ring so end of ring is aligned with locating pin as shown.
7. Install Piston Ring Compressor.
8. Remove screws and connecting rod cap from piston rod assembly being installed.
IMPORTANT: Piston must be correctly installed and positioned as shown.
Pistons marked with the word "UP" and with the letter "P" or "S" on top of piston.
Pistons with the letter "P" must be installed in the port side of engine and the word "UP" fac-
ing toward top of engine.
Pistons with the letter "S" must be installed in the starboard side of engine and the word "UP"
toward top of engine.
9. Coat cylinder bore with 2-cycle oil. Match piston assembly with cylinder it was removed
from, and position piston as described below. Push piston into cylinder.
UP
CYL 2
P
UP
CYL 4
P
UP
CYL 6
P
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Page 4A-64
a - Piston Ring Expander (91-24697)
b - Dot Side "Up" on Piston Ring
UP
CYL 1
S
UP
CYL 3
S
UP
CYL 5
S
2 Cycle Outboard Oil
a
b
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90-884294 OCTOBER 2001