Mercury 150 EFI Service Manual page 377

POWERHEAD
5. Lubricate piston, rings and cylinder wall with 2-Cycle Outboard Oil.
a - Piston Ring Expander (91-24697)
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
Page 4A-60
b
UP
CYL 1
S
UP
CYL 3
S
UP
CYL 5
S
a
b - Dot Side "Up" on Piston Ring
14
14
51081
56156
2 Cycle Outboard Oil
90-883728 JULY 2001