1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 202Get this manual
CYLINDER BLOCKCRANKCASE
Piston Pin
1Measure piston pin diameterReplace piston pin if out of specification
Piston Pin Diameter 0.55100.5512 in(13.99614.000 mm) 2Place the piston pin into the connecting rod and check for free playThere should be no noticeable free playReplace the pin andor connecting rod as necessary
3Place the piston pin into the piston and check for free playThere should be no noticeable free playReplace the pin andor piston as necessary