omc 800 convert to merc I/O outboard or keep - The Hull Truth

maxd24 · 07-05-2009, 10:10 AM

this is my first post here. I recently got an 82 grady white 241 weekender the boat has a 350 with an omc stringer outdrive the engine is blown. everyone i talk to says not to replace the engine but get a bracket and put an outboard out back I still havent decided and im asking for advice. how much hp would i need on the outboard the boat weighs about 4500 lbs thankyou i keep hearing that the omc is junk please advise

commuter boats · 07-05-2009, 10:58 AM

The OMC is junk!

Bly · 07-05-2009, 11:26 AM

If you like the boat now you will love the boat as an outboard with a bracket. My boat was an IO that I converted and it is faster more economical and I have a swim platform too.

maxd24 · 07-05-2009, 12:34 PM

which bracket did you use and what size engine should i use appx 4500lbs im getting a fiberglass guy to check out the transom if it needs to be replaced should he put in an outboard transom or an io transom with a bracket thanks im thinking 250 hp should do it

Bly · 07-05-2009, 12:53 PM

I work in fiberglass more than I should? I have a post about my prop problem and f225 from a 250 2 stroke I just posted.All the 250s are 250 hp not the same for F225? Check the transom good and if its bad there are 2 ways out. rebuild the whole transom. Or cut and chisel the wet wood out . dry completely and rebuild only to stiffen the transom and glass in two stringer extensions from original into the bracket. That is the best way In my book! It will last for ever if done right.

maxd24 · 07-05-2009, 01:15 PM

sounds good i dont know alot about fiberglass but i weigh 240 pounds and i stood on the out drive and bounced while my friend was checking for movement and it was very solid but i will get it checked by a pro piece of mind is worth it

eggsuckindog · 07-05-2009, 02:10 PM

You still have to add to an IO transom as the power comes from a different angle with an OB. A 300 Zuke or Etec would be my choice thats a heavy boat.

LouC · 07-05-2009, 03:03 PM

Not only that....the way the OMC stringers transferred power to the boat's structure...was through the stringes not against the tramsom at all...so sometimes the transoms on stringer equipped boats were built very light and for an OB conversion would likely need a complete rebuild....another option is to re-do the transom and put in a new IO package....like a 7.4/Bravo but on a boat such as a Grady your resale would be better with an OB power package...going back to the IO the weight balance...center of gravity...and handling of the boat will pretty much remain the same as it is...putting a bracket and OB off the stern may change things...I'd consult with people who have done this before before jumping in...Personally I would not have a problem with an IO with closed cooling on such a boat but some only want OBs...

maxd24 · 07-05-2009, 03:10 PM

I was considering a merc i/o conversion what kind of work is involved and where can i get a used setup maybe find a junk boat with a merc? i know the hole for the merc i/o is smaller than the omc i was an auto mechanic so the i/o would be easier to repair engine wise maybe i can get a complete sterndrive

LouC · 07-05-2009, 03:24 PM

It's a big job for sure...you are talking a complete transom rebuild...but if you can work on IOs more so than OBs you may save a lot of money that way...I would be careful about used engines unless you are in a freshwater area...here I'd only buy new (salt water)....
Now having said that...before you go ahead....what is the condition of the rest of the structure of the boat...deck...stringers...gas tank....hull/'glass etc...it's easy to get into a complete rebuild when you start one of these...so you have to be able to say you're gonna keep this boat because you'll probably never get that money back...but will have a nice boat to run for a long time...the only way to look at it....

maxd24 · 07-05-2009, 03:30 PM

well i will get back to you on the condition of the rest of the boat it feels solid i have a fiberglass guy coming to take a look at it i was planning to get a reman 350 and a used sterndrive the 350 are obtainable fairly cheaply i got the boat for a steal 500 i think the trailer is worth at least 1000 so im currently ahead not for long though

Bly · 07-05-2009, 03:52 PM

Quote:

Originally Posted by maxd24

well i will get back to you on the condition of the rest of the boat it feels solid i have a fiberglass guy coming to take a look at it i was planning to get a reman 350 and a used sterndrive the 350 are obtainable fairly cheaply i got the boat for a steal 500 i think the trailer is worth at least 1000 so im currently ahead not for long though

Thats why I suggested a Fiberglass bracket. I have been doing fiberglass work since the 60s on surfboards and a 16 ft glasspar that used to crack the factory plywood floor in a differnt place every year. Do a search on THT for my Formula 233 project. Bly That was my first Formula project. I have a new and improved bolt on V bracket that could save you a lot on rebuilding notoriusly bad old grady transoms. Believe me I have done more than my fair share of fiberglass repair on old gradies. That boat cost me $50.00 the last 233 I bought cost me $400.00 with an aluminum trailer. Just because he wanted it out of his side yard. If your fiberglass guy needs any direction on a bracket installation without making the transom do all the work contact me.