Starting rebuild thread 1987 eveirude 90hp

[86bonito]

1987 evinrude 90hp rebuild
I bought orig joh/rude factory repair manuals from ebay $10. read pages of posts here and decide to go ahead. For starters #3 piston was smashed into head destroyed it had a hole in it. Head is useless, cylander walls have some groves and a little chipped around edge. Will post pictures when get battries for camera. (tips)- photo bucket? Pulled head off to find part # didnt see any. Ebay had a set for $25 buy it now look good(but real cheap). looked at the other piston marked kd3013f2 .020 h68h9. I assume that stands for .020 over which means the motor was already rebuilt. cylanders 1,2,4 all had a psi of 120. Assuming that all cyl. have been boared .020 over can the #3 be boared again? is it worth the trouble to tear it down and drag it in to the shop and have them check? Thanks for the input I want to post the all the way through the rebuild if you think i can rebuild it again.
Threads like this have helped me so I thought I would return the favor.
Brian

 

[Faztbullet]

Re: Starting rebuild thread 1987 eveirude 90hp

Usually if the piston has contacted the head thats a sign of one of 2 things (1) wrist pin bearing failure(2) rod bearing failure. When a crossflow is running at rpm there is only about .025 thousands for top of head to piston crown. With the ports being chipped I will lean toward wrist pin failing.The piston you have is a Wiseco(not my favorite) and it can be bored up to .064 over size. Tear it down and have cylinders miked. Wisco pistons need about .0005-.001 extra clearance to prevent cold sieze of pistons. Also replace the T-stat's as this is cause of most engine failures(to cold) The part # for head should be cast into head. Also check the jets in carbs as I up jets when boring motors. You can run stock jet on std-.020 but allways go 2 sizes on .030 over.