Engine not turning after installation

[Donzi18]

Hello,

I have a 1994 5.7 350 MAG Mercruiser with and Alpha 1 drive. A bad starter chewed up my flywheel ring gear. I removed the engine to replace the flywheel, reinstalled the engine, put everything back together and now the engine is behaving as though it is seized. It ran fine before I took it out. The new starter is engaging the ring gear, but the engine won't budge. The starter is getting plenty of power. It smokes if I keep the key turned.

What could I have done wrong? I assembled flywheel, coupling, bell housing exactly as I took it apart. The only possible thing I can think of is that I rested the engine on the front mounts and the rear drive shaft coupling. In other words. I put the engine on the forward mounts first then tried to lower the engine onto the rear mounts. The drive shaft coupling did not clear a lip on the transom plate and for a brief period of time the weight of the engine was supported by the front engine mounts and the drive shaft coupling in the rear. Is there something I could have done wrong? What could be preventing the engine from turning?


Any thoughts would be greatly appreciated!!

Thanks,

Jay

 

[mkast]

Re: Engine not turning after installation

Time for dis assembly of the engine to find out why.

 

[Donzi18]

Re: Engine not turning after installation

Could weight on the drive shaft seize an engine?

 

[Donzi18]

Re: Engine not turning after installation

I did take the outdrive off before engine removal. I put the outdrive on before I tried to start. I experience this problem, and the I took the outdrive off again to make sure it was not a problem with the outdrive.

Thanks for the help!

 

[Donzi18]

Re: Engine not turning after installation

I had it resting on the coupling. I think that is what you call the piece that bolts onto the flywheel. That is the black piece that comes out of the back of the engine. I guess it is not the drive shaft but the piece that the drive shaft slides into.

As far as aligning the engine, I thought as long as you do not move the engine mounts, you don't need to re-align?

 

[jaxnjil]

Re: Engine not turning after installation

this is just guessing but might help.

pull all the spark plugs and see if you can turn it over with a socket and ratchet on the front of the crank shaft. it should turn fairly easy. also if the fly wheel or starter arnt just right and catching and binding you should hear a scraping sound
i guess it wouldn't be a bad idea next to pull the drive as the starter has to turn it when cranking. I'd have thought any problems their would have been caught when you had it off.
also verify you have the right starter



\
if it ran fine before it should run now

 

[Donzi18]

Re: Engine not turning after installation

Thank you! I'll pull the plugs and try turning by hand. The drive is off now and starter still won't turn the flywheel.

Thanks for your help and I'll update after turning by hand with plugs out and outdrive off...

Jay

 

[bustermin]

Re: Engine not turning after installation

it was working fine before you removed it, then you replaced the flywheel and now its binding, with the outdrive removed. are you sure you put the correct flywheel on? sounds like the flywheel is binding against somthing.

 

[dontask]

Re: Engine not turning after installation

Before you pull the engine have you made sure that you have the correct starter installed? If you pull the starter can you now turn the engine over by hand? Does the starter have the correct drive gear on it? You said the starter is engaging correctly how are you observing this?

 

[MikDee]

Re: Engine not turning after installation

No, ANYTIME you pull the engine you must do an alignment. As I said, I would take the outdrive back off (only six nuts) and then try to start the engine. At least it will tell you if the problem is in the engine itself or in the drive line. In any case, you need to pull the drive and do the alignment so nothing lost.

Just an FYI: Anytime I pull an outdrive I check alignment before reinstalling, even if I don't touch the engine in anyway.

I totally agree

 

[jaxnjil]

Re: Engine not turning after installation

Thank you! I'll pull the plugs and try turning by hand. The drive is off now and starter still won't turn the flywheel.

Thanks for your help and I'll update after turning by hand with plugs out and outdrive off...

Jay

hope you find it!!!!
while you will need to aline your motor-drive coupler thats not the problem now and i don't think a out of aline drive could burn up a starter in the first place.

 

[Bt Doctur]

Re: Engine not turning after installation

Most if not all ring gear damage is from hydro-lock. pull the plugs, and try to turn the motor, if it dosent turn, then using a small wooden dowel probe thru the spark plug holes, if it comes out rusty, pull the heads .
Exactly what was the cause of the ring gear failure,
Did you have a hard starting/weak,dead battery sound.That water getting into the cylinders.

 

[Bondo]

Re: Engine not turning after installation

Exactly what was the cause of the ring gear failure,

Ayuh,... I guess that's the Big Question,..??

 

[Donzi18]

Re: Engine not turning after installation

You guys are right on the money! I pulled the plugs and only on the starboard side of the block they were all rusty and getting worse as I went aft. The starboard plug closest to the stern was actually dripping wet. I tasted fresh water.

I thought the ring gear got beat up by a starter not engaging properly. I guess I was wrong and it is water getting into the starboard side pistons.

Also, with the starter off and the plugs out, the motor would not budge.

Am I totally screwed or what??? Is there a fix for this or do I need a total rebuild? What causes water in the cylinders?

Thanks!!!

 

[jaxnjil]

Re: Engine not turning after installation

chances are if its lock up now your rings have rusted to the cylinder walls.
i have had this happen to motors in the past and filled the cylinders with diesel fuel and broke them lose.
it might get you by in a pinch but i have never had one run that well. i wouldnt even try it on a boat motor given all thats at stake if it blows up on the water.

you might as well pull it and pull the heads and go from there. if your bottom end is still ok and the heads are ok you might be lucky enough to hone the cylinders and and new rings bearings ect. at this point thats the best case and a long shot. worse case complete over haul or new or different motor
as to where the water came from; cracked head or block, blown head gasket, or rusted out exhaust manifold

you still need to figure out where the water came in. till you get it out and tore down any thing else is going to be a WAG

tough luck but not the end of the world

 

[Donzi18]

Re: Engine not turning after installation

Thanks everyone for your help!