Logo

Piston rings on Mariner 60hp

Coxn

Member
Rebuilding a Mariner 60hp with probable piston slap. Each piston has two rings. They both have a dot to show which way up and otherwise look like identical compression rings. Switching them is not an issue? Just wondering because I have two of these engines and I'm hoping to rebuild with the best parts.
 
Thanks for the reply. I've got both engines stripped. Compression is better on one than another, but both sets of pistons and cylinders are scored. No point buying piston kits for any of these sorry sleeves. Some are worse than others though so, I might try honing the least damaged set and matching them with the best piston/rings I have.

Looks like a drill mounted honer will be my next tool for the shed.
 
Only option left really. This engine is too old to be spending a couple of grand on new pistons and sleeves. All I can do is put her back together the best I can, and nurse her till she drops. Shame, I like these Mariners, but every dog has his day.
 
OK, honing was fun, but not enough. I sorted out the best bits from both engines and rebuilt. She started up and idled like a dream, the best she's ever sounded in fact, but when I took her out on the water she would only run under 2200rpm. Anything more than that and she stalled out. Next morning I tried her in the tank on the hard again and she was barely running, and I can hear the piston slap creeping in again.

Guess I'll have to look at a rebore and new piston kits after all. Bring Out Another Thousand.
 
Forgot to mention, the motor had 120 psi compression when I bought her a couple of years ago. She ran well enough on that, but I was down to 115, 110, and 90 before this last rebuild. After honing, she evened out at 105 psi across all 3 cyls. I had hoped this would be enough to keep her running, but I guess not.

Just thought I'd throw some numbers up for those experiencing similar issues...
 
Forgot to mention, the motor had 120 psi compression when I bought her a couple of years ago. She ran well enough on that, but I was down to 115, 110, and 90 before this last rebuild. After honing, she evened out at 105 psi across all 3 cyls. I had hoped this would be enough to keep her running, but I guess not.

Just thought I'd throw some numbers up for those experiencing similar issues...

One last question before I BOAT for another rebuild. I haven't seen steam from the exhaust, but I suppose it is entirely possible that the block has cracked and water is getting into the cylinders. I don't see much in the way of grey sludge, but the plugs are all wet and the fuel looks unburned after running for a few minutes. Anyone had this kind of water trouble with L3 blocks before?
 
Back
Top