AQ125a won't crank over? seized?

[n_waite]

New here. Thanks for any info.

I just bought an 85 2150 Bayliner that had been sitting for six years. The PO said that the motor was rebuilt 15hrs before sitting(I have receipts). I was hoping that with Engine Release and some time I may be able to free it up. No luck so far. I have been using a breaker bar/impact wrench on the crank. I have removed the starter, head and pretty much anything else that was bolted on. The pistons and cylinder look alright, so I am not sure if that was even the original problem. The head and the intermediate shaft all turn no problem. The tensioner bearing was seized, but it is off now.

I am thinking that it must be the main bearings. Can they seize from sitting(with oil) or is the PO full of it? Before I pull the motor for rebuild, I just wanted to post to see if there is anything, that I could be missing, that could be causing this. Also, there was oil in the bellows, but no water, so I don't think it is the rear bearing. Is there a similar bearing on the front of the engine that could be frozen?

Although, at this point I am almost committed to pulling the motor.

Thanks,

Nathan

 

[Don S]

Re: AQ125a won't crank over? seized?

Remove the upper gear box on the drive and see if it will turn. http://forums.iboats.com/showthread.php?t=309095

The other thing that happens is water gets into the flywheel housing and the bearing locks up and of course the engine won't turn over. When you pull the upper gear box, if you find rust in the bellows, you can bet on the bearing.

I would pull the engine and flywheel cover and see if the engine turn

 

[n_waite]

Re: AQ125a won't crank over? seized?

Sorry, I forgot to mention. The upper drive is off. No rust on shaft/u joints. Clean oil in there, I assume it leaked from the upper drive.

 

[dennis461]

Re: AQ125a won't crank over? seized?

Sorry, I forgot to mention. The upper drive is off. No rust on shaft/u joints. Clean oil in there, I assume it leaked from the upper drive.

My bet is on the pistons...
If the head is off, can you rock the pistons slightly in the cylinders, port to starboard?
Most of the normal wear on an old engine would allow for some movement.
If the piston rings rusted, stuck to the cylinder walls, then the pistons most likey won't move at all.

Also, can you try rotating the crankshft in the opposite direction?
You said the starter is off, perhaps get a big long screwdriver in there and pry up and down on the geared flex/drive plate.

I bought an old Jeep once, had to remove the head and beat one of the pistons down with a big hammer and block of wood to free it up, ran for a couple of years after that.

 

[n_waite]

Re: AQ125a won't crank over? seized?

It looks like you were both right. Pulled the motor and number three piston was stuck and the bell house bearing is shot. I guess it is a good thing that I couldn't get the engine to turn over, as I probably would have missed the shot bearing.

Luckily the cylinders look fine. New rings and I'll put it back together. How bad of an idea is it to reuse main/rod bearings? Will a gasket set include the rear seal?

Also, is there a trick to replacing the bell house bearing? Is this the same as the pds bearing? The shaft won't slide out. Does it come out forward or backward? Does the seal have to come out first? It almost feels like the inner race is stuck on the shaft and getting hung up on the seals. I read somewhere that this is a standard bearing and that you are better off to find an aftermarket stainless rather than the VP. Any truth to this? Does anyone have part numbers? And part numbers for the seals?

Thanks again.

 

[dennis461]

Re: AQ125a won't crank over? seized?

How bad of an idea is it to reuse main/rod bearings?
Thanks again.

Well, two schools of thought, if keeping the boat and motor is pulled, replace them.

If selling the boat and the bearings still have good bronze, old timers would shim them tighter ( trimming the edges so they fit in the journals) A delicate process, must be done correctly.