90 hp wasted a piston

[Steve1122]

I was down in Bahia de Los Angeles last week and on a long run back from the big island at WOT the engine started to slow down and rattle - I immediately stopped and radioed for a tow from a buddy boat.
The engine is a 1984 - I was running around 4900 rpm for about 15 minutes when this happened. I had noticed a bit of smoke coming from the cowl area while *****ing and now I think about it I'll bet the exhaust gasket was leaking and at WOT the bottom cylinder leaned out and started to sieze. Anyway, I pulled the head and the cylinder looks like it may be able to be saved providing there's enough material left for an overbore.
Any tips before I attempt this project? I'm pretty good mechanically but haven't really gotten into 2 stroke engines much.

[boats.net]

The 1984 engines had 3 ring pistons, you might want to replace them with the new 2 ring piston's(when you order the original part number it will supersede to newer piston).

[Steve1122]

I figured out the reason why the piston started to sieze - Some of you may remember last year that I was having fuel issues - I replaced the fuel pump and the gasket wasn't in place when I removed the pump during disassembly today, in fact only one bolt was through the gasket and it was just hanging there! This of course leaves an open hole to the crankcase right by the bottom piston. I'm surprised it ran at all!

The engine is standard bore at the moment and it appears that all the aluminum from the piston will hone out leaving a decent cylinder to work with.
What is the advantage of going with a newer 2 ring piston? I was planning on just replacing the one piston and putting new rings on the other 2 if all checks OK. My original plan was to bore it .010 to .020 over and install all new stuff but my friend (performance engine guy at a local motorcycle/PWC shop) doesn't think I need to spend the $$.

What would you suggest? Are the 3 ring pistons available anywhere?
Thanks for your help!

Steve

[boats.net]

The 3 rings had a problem of sticking. The only piston you can get is the 2 ring, but you can replace the one piston and order the original 3 ring to replace rings on the other 2 pistons.