1967 60 HP V4 Evinrude - The saga continues ....<br /><br />Pulled one head and two cyls scored. Not worth cost of new pistons.<br /><br />As the block was potential landfill anyway, I gave one cyl a rub with 120 grit wet and dry paper and light oil and lo and behold, 90% of the score marks disappeared when I got through the glaze to clean metal.<br /><br />I'm guessing that the unburnt fuel was getting past the rings on the downstroke through the scores or maybe more likely ridges on the scores stopped the rings seating properly?<br /><br />Bore not out of round and still stock 3" on telescopic bore gauge, + or - .001 error in good quality vernier. Don't have micrometer. Clymer says up to .004 OK. <br /><br />Only one score mark, running from exhaust port, looks like it might stay after a hone. <br /><br />Choices are:<br /><br />1. Rough as guts clean all cyls same way and ensure get all sanding grit out then reassemble with fresh gaskets and see if still blowing great clouds of unburnt fuel out, and if any improvement go to next choice. Wastes a set of gaskets but saves a lot of time on finding out if it's likely to work. I know theres a risk I'll leave grit in no matter how well I clean it, but I can live with it as the thing is currently dead anyway.<br /><br />2. Pull it down and hone cyls and clean out ring grooves and check tolerances and if all OK reassemble and see what happens (lot of work if no improvement) or fit new stock rings if required (cost of new pistons is what makes rebuilding with them uneconomic).<br /><br />3. Forget it and part it out.<br /><br />What do you reckon?
