Run the rings that they supply with the pistons.2 or 3 thousandths of ring end gap is getting too involved.

How wide was the end gap? Cuz you would need 50 thou or more to get any great amount t of blowby. Remember, there is another comp ring in there too... I think those rings and those pistons don't like each other.

I can't tell you as it is so embarrassing LOL. I have no idea what I was thinking or doing but I really screwed this up bad. Lets just say the gap was in tenths not thousands. It is why I had so much blow by. The leakdown test was obvious something was wrong. I am just going to use the total seals the pistons came with and put it back together.

I would be surprised if it is the ring gap that caused this. I have been forced to run ring sets for a 5.250" cylinder in a 5.280 cylinder because rings were not available and custom rings were of poor quality at the time. Surprisingly there was no noticeable compression loss or oil control problems.

I would be looking at your cam and if reversion is an issue in your application. The larger the C.I. the more prone you are to reversion.

P.S. that's a great Sun leak-down tester!

Is it going back into the boat this year? My vote is do it. Then if still an issue you have all winter. And if not an issue you have all winter not wondering ih it is fixed or not.

Here are my cam specs, it was reground for my application as the motor had a small blower on it before.

Your exhaust valve closes pretty late for what I have been told is except-able. This can also depend on the drop in your exhaust, where the water is mixed, etc.

But for example, I had some reversion and mine closed 9.2 degrees atdc at .050, its all a game of what you can get away with. My new exhaust isn't going to mix the water in until the tip of the tail, but then again I don't have much drop.

What rpm do you idle at?

Even the best mechanics generally got that good from fixing their own phuk ups. It gives you a deeper understanding of how it needs to be done, lol.

The only people that don't phuck up are lazy people who don't ever do anything.

As I tell my kid everyone phucks up at times the key is to learn from it.

the cylinder walls do not look good to me, need to get a good engine builder to mic the bore/pistons to see where you are now..