1971 Evinrude Fisherman 6HP outboards Service Manual, Page 42Get this manual
Carefully scrape carbon from the ring grooves, making certain that carbon clinging to the bottom and sides of the grooves has been thoroughly removed without scratching or otherwise damaging the groovesA tool for cleaning ring grooves can be made by breaking an old ring, grinding the edge, and breaking the lower sharp edgeDO NOT damage the lower ring landSee Figure 5-15Check piston for size and roundness, using micrometerSee Figure 5-16Piston skirt must be perfectly round and not scratchedCorrect sizes are given in Section 2Before installing new piston rings, check gap between ends of ring by placing ring in its respective cylinder bore, then pushing the ring down in the bore slightly with the bottom of the piston to square it upDiscard and replace with new ring if gap is excessiveSee Figure -17Check each ring in its respective
Figure 5-13Breaking Glaze in Cylinders
Figure 5-15Cleaning Carbon from Ring Grooves
Figure 5-14Surfacing Cylinder Head
If the surface is actually warped or sprung, high