1967 Evinrude StarFlite 80 HP Outboards Service Manual, PN 4359, Page 51Get this manual
cantModerate discoloration of balls and raceways is not cause for discardSEALS aReplace upper crankcase head sealDO NOT reuse sealSeat new seal with lip facing in and flush with top of crankcase headbLower crankcase head seal should be replaced and any parts of this assembly should be replaced if damaged or wornNote "0" ring to be assembl ed in groove inside carbon sealPISTONS Check the pistons for roundness, excessive skirt wear, and scoringThe piston skirts must be perfectly round and unscratched to prevent the entry of exhaust gases into the compression chamberSee Figure 5-24Carefully remove carbon deposits from inside piston headInspect the ring grooves for carbon accumulation, excessive wear, or damage to the ring seatsCarefully 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 the ring grooves can be made from broken ring with sharpened edgeCare must be taken not to damage the lower ring landsSee Figure 5-25Check piston for size and roundness, using micrometerCorrect sizes are given in Section 2Figure 5-26Checking Ring Gap in Cylinder