1980 OMC 3.0L

[HoundsNTrout]

I'm restoring a 20' Cobia with that engine. Also sending the engine out for full re-build/replacement/exchange.

 

Anyone had/have experience with this old beast?  The good, bad , ugly or indifferent.  It was all set up for fishin off Chatham Bay, MA. Before my neighbor got ahold of it. I payed 300 including trailer which is in good shape.  
I don't think they took that sucker out in 6' waves or anything.  LOL 
But I took it out twice on the Big O out to 150 maybe 1.5'  footers at best is all I got to do before I decided to bring her back in then yank engine and do a total retore.

 

its small and weighs 1900lbs. OMC 3.0L stern drive.   NOt sure I'm fond of that ( no throttle if the drive int in full down mode ).  It does tilt to trailer and launch though. 

What would be 'comfortable' for max waves in this little thing?   I like the weight on it, seems perfect for just me and Two guys.  Its fiberglass. No cracks other than "spyder cracks' on a couple spots of the gelcoat.  Do I worry too much about those? 

Is there any home 'test' I can do besides pounding on it with rubber mallet all the way around.   LOL.  Seems real solid.

 

Thanks

 

[Chas0218]

Look into upgrading to a mercruiser engine and lower into if it is a complete rebuild top to bottom. OMC parts are becoming harder to find.

Sent from my thinking chair...

[HoundsNTrout]

Thanks. Never thought about "upgrade". I'll look into that. It does appear from searching that parts will or are becoming an issue to find.

With the engine, I can have a couple options. I would choose the total rebuild top to bottom, over say just the block and pistons and rings OR rebuilding MY engine. 
 

[rolmops]

The OMC and the Mercruiser 3 liters are both GM blocks,but the manifold and other parts are a bit different. The Mercruiser is thought to be the better engine it is still built today. There are many good second hand Mercruiser 140 3 liter engines with all the improvements that were made over the years. I am not sure that the gear cases are the same, but the mercruiser gear cases are widely available. Anyway if that old beast of yours was in salt water,then you should not waste money on it ,because the possible damage that was done to the manifold and block will come back to bite you in the behind.

Edited August 23, 2015 by rolmops

[HoundsNTrout]

Hmm, interesting. Thanks rlmps.  It WAS in Salt water he said for 3 seasons. Before that in St.Lawrence seaway. Clayton.   So I'll probably look at putting a mercruiser fully rebuilt engine and I should be good to go.  ?  THEN I'll sell it.  LOL 

 

 

[Chas0218]

When I was referring to parts I meant lower unit parts (upper and lower gear cases), manifolds, ect. I'm not sure how interchangeable the blocks are.

Sent from my thinking chair...

[HoundsNTrout]

Ok, thanks for clarifying. 

[RSF]

You may find switching from Volvo 351 (FORD Windsor? (if so-good engines)) wiring to helm may need a change-out too if Re&Re with diff OEM engines.