I don't think I would try that. I will admit I've never heard it done but if you break something in the drive then you have a frozen motor AND a broken drive.

I think your best bet would be to try and get the stripped crankshaft bolt out. Can you get a large Vise Grips on it or is the bolt too recessed in the balancer? What about a pipe wrench? If the motor is frozen it may look as if you are going to have to pull the motor anyway.

Sorry this is turning out to be so frustrating.
Shawn

 

I don't think I would try that. I will admit I've never heard it done but if you break something in the drive then you have a frozen motor AND a broken drive.

I think your best bet would be to try and get the stripped crankshaft bolt out. Can you get a large Vise Grips on it or is the bolt too recessed in the balancer? What about a pipe wrench? If the motor is frozen it may look as if you are going to have to pull the motor anyway.

Sorry this is turning out to be so frustrating.
Shawn

Thanks, well then before I pull it I'll remove the logs and try to tap each cylinder in firing order through the spark plug holes. The bolt for the crank was missing when I got the boat. I ordered the correct bolt for the motor but it won't thread into the threads inside the crank, they are stripped or either they broke the bolt off in the crank.

 

Sounds like you need another motor. Get a 350 this time around, 96 or later

 

I had my 305 stuck when I didn't use it 8 years and I shot WD40 in all the cylinders and let it set overnight then next day shot some more in cylinders. There was just enough room to get a pipe wrench on the output shaft in front on the transom behind motor. Put a short pipe on the pipe wrench handle for extra leaverage and when you get it loose work the motor back and forth a little before turning it too far so it loosens up the rust. I then put fresh gas in tank and fired it up and its been running fine for years and doesn't use any oil. You don't want to try turning it with the crank bolt, you'll just break it off, it wasn't meant to be used for that, and if there isn't room for wrench behind motor pull outdrive off and turn with output shaft.

 

Well I will definitely look into that, that might just be the trick thanks

 

Did you ever see the engine run before the layup? If not I would think there is a good chance that the crank bolt was stripped by the previous owner because the engine was already locked up. Perhaps more info might help but this engine could have been hydro locked years ago - I would just look into getting a new block. Perhaps pulling the heads might give you a better view of whats going on before pulling the engine.

-Kevin

 

I didn't see it running and previous owner "said" he never got the chance to crank it cause he fell off the boat one day and broke his leg he had it sitting for a year. But says it was sitting for years before that. someone was def. fooling with it because the crank bolt was gone and there is a small hole looking at the teeth on the flywheel. I think someone tried but didn't put a lot of effort into it. Oil is fresh and seems like it was winterized but who knows I'm just going through the motions now. I'll pull the heads this weekend if nothing else works

 

unbolt the crank pulley (3 bolts) take the pulley off and thread the bolts back in.....lock a pry bar (or similar tool) between two of the bolts and turn it over......the best solution to free a stuck motor is a 50/50 mix of ATF and Acetone.....good luck

 

Good advice if the OP wants to try to spin the motor.

 

ATF is great stuff it will clean the engine inside if you put 1 QT in the engine oil in a car it will free valve lifters in a car.

 

How is the OP suppose to fix his thread stripped crank and a hole in his ring gear without pulling it, and seized as well?

ATF right ?

 

why dont you read his question again......he did not ask for advice about replacing his motor (or even getting it to run)......he simply asked how to turn it over given his situation.......you seem to be looking for a fight......

 

"Small hole looking at the teeth on the flywheel"

I would bet that would spin just fine. Yup good advice

 

The crank pulley is the one where the bolt is broke off and he can't get the new bolt in, the pulley with the 3 bolts is the water pump pulley.

 

It’s also possible that the engine won’t turn because the drive is seized....

Step 1, remove the drive (gonna need to do this anyway to service the drive, and most likely replace bellows, also needs to be removed to swap out the engine...)

With the drive removed, try and rotate the drive input shaft - nice and free, graunchy, or stuck?

Now look for ways to fix the engine....

 

A Little closer to figuring it out.

 

Not sure what all that means....

 

Wow that is tight in there - looks like an engine pull just to do a set of manifolds. If the rest of the elbow is rusted as bad as what we can see I would guess the water jacket was breached and the the engine hydro-locked. Just my opinion YMMV.

-Kevin

 

Reading the posts and viewing the pics you need to :
shift into fwd, remove the drive to pull the motor to find out why the rear housing is spaced off the block with washers.
Second who was the butcher who holes the rear housing to turn the flywheel?
Some people should not be let near a boat let alone to try and fix it.Flywheel appears a bit rusty so suspect a high bilge level allowed water into the block and siezed it.
Being a fairly new vortec engine were new manifolds and risers installed with the new motor. If not, suspect a bad/no winterization issue
After saving and enlarging the pics I see no evidence of oil traces anywhere? Should have been some residual oil is the motor was ever running.
If you are serious about turning the motor, pull the drive, get a old inputshaft and weld a T handel on it, insert into coupler and try to turn the engine

 

Yep going to pull the Outdrive this weekend, currently won't shift into forward or reverse, but It was shifting before I started trying to crank it with the starter. None the less this is good practice lol. By the time I finally get on the water I'll be well versed in the mechanics of it all.

 

Agree with Bt. Why is there no oil residue in the rockers? Maybe it never did run. I am guessing this Vortec replaced a pre Vortec which uses a smaller flywheel. Would explain the washers trying to make room. I would remove the drive and pull the engine as suggested and you may find yourself lucky and find it to be bound in the housing. Can you get any endplay out of the crank?

 

Oil pan is full of clean oil so I'm not sure why there isn't any up top, but she finally turned over for me. Not really sure what the issue was but I couldn't get the Outdrive off it only pulled apart from the case 1/4". The previous owner stated that when he bought it the person he bought it from said it only had 36hrs since the rebuild and then it sat for who knows how long. The last time it was registered was in 2003. I did run into an issue with the steering system it was seized hopefully it will free up if I can get the engine running and the power steering fluid circulating. Now on to getting it running. Thanks for everyone's input i really appreciate it.

 

Congrats on the free turning engine, your perseverance paid off.