Engine seized 4.3L OMC-please help!

[asubrew]

Hello! I have a 85 Wellcraft Elite with an OMC Sterndrive which orginally had the 3.8L V-6. The previous owner spent the $$$ to put in a brand new 4.3L V-6 and allowed water to get into the carb and seized the engine. I know, I know! I have been researching this online and here's what I've done so far. If you can, please provide any input or alternative suggestion. Thank you in advance.

1-Took off the carb and spark plugs and poored Marvel's Mystery Oil down intake (where water came in right?) and cylinders.

2-Waiting a week or two to let the oil penetrate...

3-I have tried rocking the flywheel back and forth with a 5/8 inch socket and I get some movement and noise, but it won't move past a certain spot.

4-I plan on waiting another week to let the oil penetrate and then try turning it with my 48" breaker bar.

What do you think? Please help as this boat isn't worth another brand new rebuilt.

 

[DJ]

Re: Engine seized 4.3L OMC-please help!

Are all the spark plugs out? If not remove them. It may be hydrolocked.

IS the outdrive in nuetral?

Are you sure the outdrive is not the issue?

 

[Coors]

Re: Engine seized 4.3L OMC-please help!

pull the drive, then try to spin it.

 

[asubrew]

Re: Engine seized 4.3L OMC-please help!

Thank you for all your fast responses!

The spark plugs are all removed.

I know the engine is seized because I can see a little rust in two of the cylinders (with intake values open). I am not ruling out the drive at all.

How do I ensure that the drive is in neutral? Should I pull the drive before trying to spin it? Is this much work to do? I have the manual on order.

I have all the belts removed. Is there anything else I should check before cranking it further with the breaker bar? I won't mind doing a little ring damage since they are almost new.

I appreciate your help. Happy Holidays.

 

[asubrew]

Re: Engine seized 4.3L OMC-please help!

By the way...the movement I GOT was minimal. I stopped when I heard a little metal against rust noise in the engine when I was trying to turn it with a normal wrench. Now, I don't want to put too much pressure on it without checking with the experts. Thanks again.

 

[DJ]

Re: Engine seized 4.3L OMC-please help!

If it's that rusty, do yourself a favor and remove the heads.

 

[180shabah]

Re: Engine seized 4.3L OMC-please help!

Removing the drive is not difficult, but it is heavy. Since this is a "new" boat the drive needs to come off anyway to check engine alignment, condition of the gimble bearing, ujoints etc. It is also the first step in removing the engine which it sounds like you may end up doing.

Also, YOU need to determine the source of the water, don't just take the previous owners word. A leaking exhaust manifold/riser/elbow will dump water back into the engine. It would really suck to get everything running, just to be right back in the same place a week later.

 

[180shabah]

Re: Engine seized 4.3L OMC-please help!

Oops, I glossed right over the '85 and used to be a 3.8 part. You probably have a stringer drive so you can ignore the above about gimble bearing and engine alignment - they don't apply.

Still need to test the manifolds though.