is 250 hp enoulf?

[seabird 73]

im in the process of repowering a 1973 23 ft sea bird. it orginonaly had twin 140 hp omc 3 litier i/o. getting ready to start fitting the new transom. then a outboard bracket. my question is 250 hp enoulf? that is what i have budgeted. the boat will be used for fishing offshore ponceinlet and i would like to take it to the gul stream (40-60 miles out). is it possible to get a bracket that i could put one motor on then when i get a second rearange and rig for 2? thankyou or your help, mike

 

[slasmith1]

Re: is 250 hp enoulf?

I would not reccomend to anyone that they repower a boat that was designed for i/o engines with an outboard for many reasons first it would often cost far less to purchase a boat that does what you want for far les than time + materials. second you are significantly changing the weight distribution of the boat and it will never handle properly after you do this. but 250 hp should move that boat

 

[JB]

Re: is 250 hp enoulf?

I agree with slasmith for several reasons.

First, I wouldn't go 40-60 miles offshore with a single powerplant unless in convoy with other vessels. That means if I were rigging a boat for that I would insist on dual engines. In your case they would be 115 to 130; preowned if the budget requires.

Second, I don't remember ever seeing an I/O to outboard conversion that turned out as the converter planned or wished. Oh, I take that back. I do remember a SeaCamper that was converted from I/O to outboard that the owner was happy with, but he never left the ICW with it. The SeaCamper was designed to be an outboard. . . .um. . .boat originally. The I/O versions were a compromise.

I suggest that you consider a different boat; one designed to be powered with twin outboards.

 

[DJ]

Re: is 250 hp enoulf?

Since you're rebuilding the transom anyway, I'd consider repowering with twin MerCruiser or Volvo 135 HP I/O's.

The weight distribution will be right and the weight nearly identical with added performance.

The price would be very similar to a new 250 HP outboard.

 

[tashasdaddy]

Re: is 250 hp enoulf?

totally agree with DJ. too many have been unhappy with their conversions.

 

[seabird 73]

Re: is 250 hp enoulf?

thanks for the info, being an auto mechanic i would much rather have a 350 chevy than anything else. the boat had 3 litier omc. it had set undercover for 9 years. the boat is in great shape but the motors were shot. plus i dont like omc stern drives. that is the reason for repowering. what would be involved in installing a 350 with merc sterndrive? thanks mike

 

[kaferhaus]

Re: is 250 hp enoulf?

I put several thousand hours on a OMC sterndrive and know plenty of other folks that have too.

Those units got a bad rap from "bad" owners who never maintained them in the first place.

If the engines that were in the boat are re-buildable you'd be far better off in the wallet by just using what the boat came with, not to mention the handling issues you'd be dealing with by making changes.

Going to a single I/O would present it's own problems with having to re-engineer the hull.

To each his own but I'll never understand folks trying to "better" what the designer did.

If you're dead set against the OMC drives then replace them with something else. Trying to reinvent the wheel should only be done out of desperation, not by choice.

 

[slasmith1]

Re: is 250 hp enoulf?

Not to be the naysayer here but I don't get why anyone would go from a twin setup to a single. You lose far more than you gain. those 3.0L blocks are either ford or gm the only thing about them that makes them omc is the drive.
If you switch to single setup you lose the redundancy of having two mains for off shore use (easier to limp home if something goes wrong) and the biggest thing you lose is ease in docking and low speed control that you can only get with twins. when you try to take on this type of thing you are better off spending a little extra to find the boat that already has what you want than trying to spend a lot more making something you don't care for into something you won't care for.

 

[seabird 73]

Re: is 250 hp enoulf?

the reason i am going with this boat is that it was free. it is a solid boat, and it has a solid gator trailer. the motors are shot. im trying to find the best way to repower. i grew up on a lake in michigan and the people with omc motors spent more time working on them than driving. i also noticed mercrusier allways out performed omc. my family had outboards, mercury.

to me this boat is worth the effort. the hull is in exclent shape. the transom was not rotted out. the only reason i am replaceing it is the outdrive holes. after reading your responces i have a lot to think about. if i was to repower with gm mercrusiers which outdrives would you recomend? would the dual steering on the boat work with mercruiser?

i plan on spending plenty of time working on this boat. i have a 16 ft center councle with a 50 hp to fish from while i work on it. but when completed, i want people to say wow! some of you may think im crazy. this boat is my pet project and i will complete it. i am greatfull for all your advice please keep it comming. i have pics of the project, but i have to figuer out how to post them.
thankyou mike

 

[ezlucas]

Re: is 250 hp enoulf?

I agree w/ the post above. The newer 135 I/O would be better. More powerand virtually no sawing.

 

[DJ]

Re: is 250 hp enoulf?

As I satated above, since you're thinking of reworking the transom anyway.

Plugging and reglassing the OMC holes is not that hard. The mounts for new(er) MerCruisers or Volvos would be very similar.

Personally, I would go with Volvos, if I went that route.

They use the same GM base 4-cylinder but the Volvo drive is far superior than the Alpha MerCruiser. The Volvos shift better and are far more durable.

Going to a single V-8 would be difficult and going backwards, IMHO.