Mercury Optimax 115 Service Manual page 266

6. Install new piston pin lockrings (one each end of piston pin) with Lockring Installation
Tool (91-77109A1).
7. Make sure lockrings are properly seated in piston grooves.
a -
b -
Piston and Piston Ring Combinations
153 CU. IN. (2508 cc) MODELS
All 153 cu. in. (2508 cc) models have two half keystone (half tapered) rings.
Pistons with two half keystone (half tapered) rings
0.056 in. (1.4 mm)
0.056 in. (1.4 mm)
a -
b -
90-855347R1 JANUARY 1999
b
a
Lockring Installation Tool (91-77109A1)
Lockring
a
Half Keystone (half tapered) Piston Ring
Enlarged View of Piston Ring Grooves
51086
b
POWERHEAD
a
51086
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