Help frozen b94 115hp

While I was barely moving fowa

While I was barely moving foward the motor made a very quiet clunk and stopped. I couldn't turn the flywheel no matter how hard I tried. After a tow off the lake I decided to take out the spark plugs and see what was going on. The plugs looked fine but one of the pistons has a ton of carbon build-up on it. It looks like it had so much carbon that the spark plug was leaving an indent where it was hitting. After pulling with all my might I got the motor unfrozen. The flywheel turns fine but I'm worried about the condition of the aforementioned piston. What should I do from here? Is there anyway to clean the piston off without causing some major damage? Why did it lock up and now it feels fine? Thanks in advance for any help.... I miss my boat already....

"Try running a compression che

"Try running a compression check, and let us know what your numbers are. Seems like the best place to start."

"Bad news. Don't use that

"Bad news. Don't use that motor until you've pulled the head from that cylinder and done a thorough inspection of the cylinder from as many sides as possible, up to and including removing the exhaust ports.

Possibilities:
o Starter motor jam
o Sparkplug broken in cylinder
o Motor inhaled a broken reed
o Broken rod/wrist pin
o Piston disintegration

Guesses based on experience: Although it is possible that a rod has gone, it is more likely that the top ring land has blown and splattered ring bits all over. The jamming of the motor was probably caused by a peice of the ring lodged between the piston and the exhaust port.

The clue is the carboning and the dent in the top of the piston. That cylinder has been experiencing preignition (perhaps from a marginal plug or mixture problems). The preignition has started pounding a hole through the piston and probably has eroded the top ring land. Although OMC has tried beefier pistions with a thicker land, this type of problem still occurs."

"From the year given, it indic

"From the year given, it indicates a 60 looper, but how to hit the spark on that model you need a 1cm build up! Is this a 90 cross engine?
SL in mod number = 60 loop, TL = 90 cross"