Power for an Off Shore 24.5 ft

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Nanoose Bay

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I have recently purchased a 24.5 ft. Off Shore and the twin 175 evinrudes appear to be destined to be a buoy anchor. I have a chance to buy a 225 Evinrude with 1 yr. warranty but I am concerned that may not be enough power. Appreciate any feedback. Thanks
Nanoose Bay
 
Don't have experience with that model but from what I can gather, seems very underpowered. GL
 
Nanoose Bay,
I ran a 24' offshore for ten years. It was powered by twin 140 2 strokes . That was plenty of power for the boat. It was loaded with 150 gallons of fuel, hardtop , 10 gallons of fresh H20, usually 3 to 4 grown men and a host of tackle. I had zero power issues.
In your case going from 350 hp to 225 hp will seem as though you're stuck and can't get going.
With that being said there are awful lot of 24's running around with single 200's, 225's and 250's on them and they seemingly have no problems.
If your boat is a notched transom boat, the conversion from twins to a single will not be that big of a deal. On the other hand if you have a bracketed boat that is a whole nuther can o' worms.
Power wise the 225 will be just OK .The mounting and rigging will be the issue.
 
Need nore info. What year is the boat?... bracket, notched transom, etc?

Are you sure it's an "Offshore" model? Never heard of a "24.5" Offshore.

The last year for the Offshore model was 1991, then it became the "Explorer", which ran up until 95. the Offshore and Explorer models had the same basic specs. Length was 24' 1" and a max hp rating of 300, (actually, pre 86 Offshore models had a max hp rating of 280).

In 96 the Explorer was replaced by the Voyager. It is a completely different boat with a length of 24' 9" and a max hp rating of 350.

The reason I mention all this is beacause of the "twin 175's" you mention. Again... doesn't make sense for an Offshore model, so maybe you have a Voyager?

If it is an Offshore or an Explorer, yes... you can get away with a single 225. It is enough power for that hull. No speed demon, (a 250 would be better) but ok. And again, without knowing the specifics, (bracket, notched, etc) it's tough to say how difficult the replacement/installation would be, (going from twins to a single).

If it's a Voyager... no, I don't think a 225 enough power. The hull is longer, wider and around 500 pounds heavier.

If it were me, since the boat's already set up for it, I would stick with twins... much better capabilities. Imo, ideally, you want the hp to be as close as possible to the max rating, but I wouldn't exceed it.
 
Hey Nanoose I am just south of you in Cobble Hill. I run a 87 offshore 24. I think you may have issues with that single 225 popping out of the hole. Mine is powered by a 250hp IO and that seems to do the job fine but struggles a little if I am heavily loaded. I take it that the 225 is a 2 stroke which should help somewhat.
 
Thanks for all the great info, it is definitely a 1985 off shore, sorry, length is 24' 1". The 225 hp has been quoted as installed by an individual that owns a large marine shop and has over 25 years marine experience.
Thanks again, Wayne
 
Nanoose Bay said:
Thanks for all the great info, it is definitely a 1985 off shore, sorry, length is 24' 1". The 225 hp has been quoted as installed by an individual that owns a large marine shop and has over 25 years marine experience.
Thanks again, Wayne
Click to expand...

In that case, I would go with the 225.

Offshore models of that vintage were available in 3 different versions... a regular notched transom, (model 240) an i/o, (model 241) and the Sea Drive version, (model 242). Here's a link to grady's 1985 catalog, (pdf) - http://www.gradywhite.com/customer/cata ... s/1985.pdf
You didn't specify what set up your boat was. Assuming it's a 240, that should be one of the easier and cheaper, (hopefully) conversions.

Again, the 225 will be adequate power for that hull. After everything is done, it may be worth exprimenting with different prop sizes. A standard 15 x 17 should be ok, but if your gona have a lot of people and gear, (heavy) it might be worth running a 15 x 15.

Also, imo, it would be a good idea to have someone thoroughly check out the transom and stringers. Preferably a 3rd party surveyor. It would not surprise me one bit, if a boat that old, had some transom problems. Imo, it's worth spending a little now, (on a survey) then to just go a head and invest a large amount of money, and find out you have a major structural problem later on.

I'm not saying that your marina shop owner is shady or anything, but I would think his main concern is making the sale, (motor and/or install $). Where as, a 3rd party surveyor will give you an unbiased opinion, as well as a thorough report. Something your insurance company may require anyway.

Good luck and I hope it all works out well.
 
offshoe

I have an older offshore and it runs great with a single 200hp johnson ocean runner. I am running a 15x15 prop loaded down close to 40 mph. Actually have to back the throttle down to keep her in the happy range. Hope to see another of these old beasts on the big pond
 
Offshore 24 ... power

I saw this thread and I have a lot of thje same questions as well. I have a 1980 Offshore 24. I got it with no power. I am leaning toward a four stroke, but would consider a 2. I have good dealer support in my area for Mercury and Suzuki. I put a lot of hours on the motor each year, running charters and commercial fishing. If I get a 4 stroke - how are the Verados? I have confidence in Suzuki 4 strokes because a lot of the guys I fish with use them , but Verados I dont know too much about. How does an Opti compare to an E-tec ? The e-tec dealer is a little farther away, but not too far. How many horses do I want? 225-250 seems to be the answer, but how many more can it take. Lastly, how much weight can I expect to allow for a motor? A 225 Suzuki is 580 +/- and a 225 E-tec is 510. Is this weight worth worrying about? This is alot of questions I know, but I have made some mistakes re-powering other boats and any help is appreciated. Thanks
 
Re: Offshore 24 ... power

kevine said:
I saw this thread and I have a lot of thje same questions as well. I have a 1980 Offshore 24. I got it with no power. I am leaning toward a four stroke, but would consider a 2. I have good dealer support in my area for Mercury and Suzuki. I put a lot of hours on the motor each year, running charters and commercial fishing. If I get a 4 stroke - how are the Verados? I have confidence in Suzuki 4 strokes because a lot of the guys I fish with use them , but Verados I dont know too much about. How does an Opti compare to an E-tec ? The e-tec dealer is a little farther away, but not too far. How many horses do I want? 225-250 seems to be the answer, but how many more can it take. Lastly, how much weight can I expect to allow for a motor? A 225 Suzuki is 580 +/- and a 225 E-tec is 510. Is this weight worth worrying about? This is alot of questions I know, but I have made some mistakes re-powering other boats and any help is appreciated. Thanks
Click to expand...

Owners manual - http://www.gradywhite.com/customer/cata ... s/1980.pdf

Max hp is 280.

If it were me, I'd go for a 250 E-tec.

If it has to be a 4 stroke, my second choice would be the 250 Suzuki, (250 and 225 weigh the same).

The scuppers on Grady's, (especially the older one's) sit low in the water to begin with, so I wouldn't be comfortable adding more weight on the back.
 
I have a 1995 Explorer 24, Officially called the 246G. The "G" designates a single bracketed outboard engine.

I ran it with a 225 Johnston for 5 years until I repowered with a 225 Mercury Optimax. Top speed with full fuel, 4 people, fishing gear and enough beer to wipe out a Marine platoon was around 40MPH, either engine. Best ecomomy is at about 29 or 30 MPH and at that speed I can trim in light seas to about 2.2 MPG with the Mercury. Except that the Mercury Optimax was much better on fuel I don't think either ran much faster than the other.

Ed
 
Have a 87 24 offshore with a 2003 HPDI yammy . 4000 rpm 27 mph. Fully loaded with a hardtop. Full throttle 5500 rpm 34 mph. hope this helps.
 
I have a 240 offshore powered by a 225. Boat is specificly rigged for diving only. I carry 10 - 12 tanks daily. 3/4 tank of fuel - 15x 17 wheel the boat works hard to cruise at 18 kts.
 
Keysdiver said:
I have a 240 offshore powered by a 225. Boat is specificly rigged for diving only. I carry 10 - 12 tanks daily. 3/4 tank of fuel - 15x 17 wheel the boat works hard to cruise at 18 kts.
Click to expand...

Sounds like you need a 15 x 15. Might be worth giving one a try.
 
24 offshore, full transom, bracket, 225 no problem 40 mph EZ. get 1.9 mpg according to fuel flo. little sluggish out of the hole though, spinning a 15x17 hope this help
 
24 offshore

I'm looking at a '90 24 w/twin '03 opti's. I haven't seen the boat in the water yet. Any one familiar with this setup? Will it be taking water in from the scuppers? And is the ride as bad as some make it out to be?

Mark
 
only way to know with the repower is to see it on the water, there is too many variables to say yes or no.

as far as the ride goes, all i hear on this website is how terrible the ride is on older gradys....its fine. you will feel a chop but within reason...

a. its going to get you where you want to go
b. its going to get you home.

i'm the kind of person that gets a kick out of spray coming over at 45mph clinging to the wheel....
 
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