You have gone this far, and if it were me I would split the cases and make sure all good there and replace what isn’t.

I am still concerned about just what it was/is that locked this engine up so hard.  You don’t see any evidence of problems when looking into the exhaust/intake ports?   Was it rusted?   Whatever was/is wrong seems like more than the usual rusted rings/cylinder syndrome.  I fear that attempting to run the engine now may further damage it.  I guess if it were mine, I would remove the intake manifold and try to have a peek inside the crankcase(s), perhaps you will see evidence or rust or mechanical damage.   Looking through the ports, were the rings rusted/stuck in place?

This has been a long thread so forgive me if I don’t remember all the details.  Did you ever drain/inspect the gear lube, or remove the gearcase to see if it was the problem binding up the powerhead?

At this point, only you can make the decision on what to do next.  If you decide to put it back together and run it, be very careful.  Run the engine for awhile at lower RPM, keep a sharp ear open for strange noises.  I just don’t want the powerhead to be destroyed if something more is wrong, then it decides to grenade while out on the water.

Ghost_n_the_shell wrote:

Don wrote:

I am still concerned about just what it was/is that locked this engine up so hard.  You don’t see any evidence of problems when looking into the exhaust/intake ports?   Was it rusted?   Whatever was/is wrong seems like more than the usual rusted rings/cylinder syndrome.  I fear that attempting to run the engine now may further damage it.  I guess if it were mine, I would remove the intake manifold and try to have a peek inside the crankcase(s), perhaps you will see evidence or rust or mechanical damage.   Looking through the ports, were the rings rusted/stuck in place?

This has been a long thread so forgive me if I don’t remember all the details.  Did you ever drain/inspect the gear lube, or remove the gearcase to see if it was the problem binding up the powerhead?

At this point, only you can make the decision on what to do next.  If you decide to put it back together and run it, be very careful.  Run the engine for awhile at lower RPM, keep a sharp ear open for strange noises.  I just don’t want the powerhead to be destroyed if something more is wrong, then it decides to grenade while out on the water.

Hi there!
Lower gear case is off. There was about a shot glass of water that came out before the fear oil – which besides the water, looked great. The lower spins freely and seems good.

I took off the exhaust cover and bypass cover during the process – and there was very light rust haze in the cylinders. When it finally freed, the oil on top of the cylinders was rust coloured. I think it may have been simple rust haze sticking them, and the fact that the one piston stopped TDC made it very hard to get movement.

At this point I am going to remove the power head and pull the pistons and do a bore / gauge check. I’m just researching as best as I can before I do that – as this is as far as I’ve gone into any small engine.

Well, if all you saw was some rust, then it may be worth cleaning up the cylinders with a scotch brite pad, putting the covers back on and starting it up.  Like you say, the pistons being stuck all the way up and down may have hampered your progress.  Looking in the exhaust ports, do the rings look free, or do they appear to be rusted in place?

I hesitate to advise pulling this thing all apart, especially if you have not had past experience.