1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 157Get this manual
Piston Ring Installation 1Install the oil ring components as shownAlign upper oil ring rail ends with locating pinSpread rings just enough to slip over piston
Piston Installation
1Align piston ring end gap as shown
End End End End End
Gap Gap Gap Gap Gap
- Top Compression RingSecond Compression RingUpper Oil Ring Rail (Align with Locating Pin)Oil Ring SpacerLower Oil Ring Rail
a Lower Oil Ring Rail Lower Rail has Flat Ends Upper Oil Ring Rail Upper Rail has Notched Ends Oil Ring Spacer Locating Pin (Align Upper Oil Ring Rail Ends with Pin)
NOTE: Cylinder bores must be clean before installing pistonsClean with light honing, as necessaryAfter honing,clean cylinder bores with water and detergentAfter cleaning, swab cylinder bores several times with engine oil and clean cloth, then wipe with clean dry cloth2Lubricate pistons, rings, and cylinder walls with engine oil3Install each piston in its respective cylinderNOTE: Install used pistons into same cylinder from which they were removed4Use Piston Ring Compressor (FT2997) to compress rings5Position the "UP" mark on the piston toward the flywheel sidePush each piston into the cyl inder until all rings enter the boreIMPORTANT: Position the "UP" mark on the piston toward the flywheel end