I have a 1987 yamaha pro 50 hp did a compression check and #1 100 #2 102 #3 35.I removed the head to look at number 3 piston and cylinder,The cylinder did not look scratched at all but the piston had about a half of a pencil eraser chunk missing from the top of the piston head.I have another same exact motor that blew the same piston.I was thinking of pulling a good piston out of that motor and putting it in my newly blown motor,And buying a ring kit. Im kinda worried about the reason it blew ,still not knowing why. Only thing I noticed was a chrip the motor made when backing off of full throttle.A friend said it was a lower crank gasket or the gasket but never looked into it.Wish I would have now.I am pretty mechanically inclined with car motors,and done so basic stuff to boat motor but never replaced pistons and ring in a outboard.Is this a very hard job.And what kind of tools am I looking at having to have. should I change all the rings or will I be Ok just changing the #3.Not really sure what I am going to do yet.Any info on this project will be much appreciated.
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