Piston/Crankshaft Reassembly; Piston Assembly; Piston Ring Installation - Mercury FourStroke 2.5 Service Manual

Powerhead
12. If the valve seat contact area is too narrow and situated near the bottom of the valve face, use the 60° cutting tool to cut
the bottom edge of the valve seat. If necessary, use the 45° cutting tool to center the area of contact and set its width.
a

Piston/Crankshaft Reassembly

Piston Assembly

Assemble the connecting rod to the piston. Lubricate the piston pin with 4‑Stroke 10W‑30 Outboard Oil. Install the piston pin
and secure with a new piston pin clip.
IMPORTANT: Ensure the "UP" on the connecting rod and piston are facing the same direction.
c
c
b
a
c
Tube Ref No.
4-Stroke 10W-30 Outboard
110
Oil

Piston Ring Installation

IMPORTANT: Use caution when installing piston rings to avoid scratching piston.
1. Install oil ring, second ring, and top ring.
IMPORTANT: The "T" on the first and second ring must face the crown of piston.
Page 4A-34
a - Previous contact width
60°
20981
a - Connecting rod
b - Piston
c - Piston pin clip
d - Piston pin
d
6366
Description Where Used
Piston pin
90-8M0065421 NOVEMBER 2012
Part No.
92-858045K01