Re: 1970s 1150 mercury 115 hp top piston has metal plate over plug hole???
I would put money on that being the culprit.The top cylinder does not get the complete oil/gas mixture like the rest do.That is the main reason for that line being there.Just rebuilt a 1400 with the top cylinder fried and a broken oil line staring at me, motor was bought that way..the oil feed line that runs from the bottom of the block to the top was cracked and clearly needs replacment. how would that make the top piston melt down tho? doesnt that just feed the main bearing?