1988 115 hp with "stuck rings"

I have a 1988 Yamaha 115. It's old, but it doesn't have a lot of hours on it. Last year, It ran hot and shut off. I have discovered that there was no actual piston damage, but in one cylinder there was a cracked thermostat cover and water leaked badly. On that cylinder, the piston expanded and now that it has cooled down, the rings are compressed and stuck. I've been told that there are products that you can put in the gas or spray and let sit in the cylinder that will loosen up the rings.
Again, the piston is in tact and there is no visible scoring of the cylinder.
Any ideas on this would be greatly appreciated. I certainly don't want to have to dismantle this block to replace the rings.

Thanks,

Re: 1988 115 with "stuck rings"

hi, it sounds like your engine is seized due to poor cooling system and you have to overhaul the engine.

Re: 1988 115 with "stuck rings"

Nope. One cylinder has no compression due to compressed rings. The engine runs. Just doesn't idle well and and doens't make high RPM's.

Re: 1988 115 with "stuck rings"

That`s why I am saying that you have to open the engine to inspect why the ring getting compressed. Might be you have to change the piston and the rings.

Re: 1988 115 with "stuck rings"

That's what I'm trying to avoid. Sometimes when you have an overheating situation, the cylinder contracts and the piston expands causing the rings to be forced into the piston groove with force. Once the motor cools, the rings usually spring back. Sometimes the rings are wedged into the poston groove and if they don't spring back out of the groove, you have a cylinder with little or no compression. Both OMC and Mercury make their own "stuff" that you pour into the cylinder and let it soak overnight and it will ofter loosen up the stuck rings and you're back in business. I was just wondering if Yamaha had a solution that they recommended. I found the Yamaha "stuff" it's something you mix with your gas and run the motor. I don't like that idea, so I got the OMC stuff and seems to be working. Sometimes, it takes a few treatments before the rings loosen up and compression is restored to normal. I've been working on outboards all my life. Now that I'm 50, it's just not as much fun as it used to be tearing one down. I'm learning to work "smarter" in my old age and use chemicals and patience to correct the problem if possible. I remember when I almost enjoyed having a motor screw up just so that I could tear it down, bore it out, re-jet the carb, shave the head.......... Now, just the thought of all of that makes me tired! Thanks for your suggestion. I'll see what I can accomplish without tearing it down.

hi, I really don`t have any idea is their any stuff like this but try it, if it`s fine then touchwood and do let me know the product name.

Wow this is and old post but I have nearly the exact problem on 1997 60hp Johnson. Top and bottom cylinders have compression of 120 and middle has 60...no scoring on cylinders. I was advised to use some Evinrude/Johnson Tune in a can but that takes running the engine and I want to do things before that so I looked into solutions that can be done before the running fix. It ran before I did a compression test but when finding the compression problem I kept searching I was told that a 50/50 mixture of Automatic transmission fluid and acetone works wonders and there are other unseize products in a can. I did not see any solutions on your post so I thought you might still be interested in a solution. Good Luck.