I am a new Grady owner of a 1990 Offshore 24. I am going to buy an outboard for it. I am wondering if a Suzuki 4stroke 225 of 300 is going to be too much weight. The dealer says I will be fine, and I am inclined to agree, but I would like to talk to someone who has done this.
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Repowering a 1990 Offshorre 24
- Thread starter kevine
- Start date
richie rich
Well-Known Member
what did you have there before? in the size you're looking at, a 4 stroke will weigh between 60-80lbs more than a 2 stroke...it can have an effect if the aft end of the boat is already sitting low in the water....hows the scupper waterline?
Thanks for writing. The boat had an older Yamaha 175 2-stroke. I havent had it in the water with that motor on it, so I dont know how low it sat.
catch22
Well-Known Member
I had an 85 with a Sea drive. Hp was around 205 and it was somewhat of a dog. Imo, 225 is a decent minimum for that hull. I can't imagine how poorly that boat ran with a 175 on it.
The maximum hp rating for a 1980 24 Offshore is 280. I don't recall what year, (maybe early 90's?) but they increased it to 300. Any way, I wouldn't even consider the 300 because of that rating. Also, the 300 weighs 600. Typical v-6 2 strokes come in around 480 - 500. The 225 and 250 both come in at 580. My choice would be the 250.
The maximum hp rating for a 1980 24 Offshore is 280. I don't recall what year, (maybe early 90's?) but they increased it to 300. Any way, I wouldn't even consider the 300 because of that rating. Also, the 300 weighs 600. Typical v-6 2 strokes come in around 480 - 500. The 225 and 250 both come in at 580. My choice would be the 250.
My previous Grady Offshore 24 had twin 140 suzuki two strokes on a Grady drive The motors were 375 lbs apiece. Thats 750 lbs of motors on a bracket. The model was a 242G .
There is one I know of on Harkers island that originally had twin 140 evinrudes , then 130 evinrudes, now it has a single 300 Yam. HPDI on it . It is not a bracketed boat but an open transom model.
I cant imagine not being able to put any 500 to 600 lb motor on that boat , bracketed or open transom model.
I can also guarantee the op's boat was a dog with a single 175 on it. It must've had a 14 or 15 pitch prop on it to even plane off.
There is one I know of on Harkers island that originally had twin 140 evinrudes , then 130 evinrudes, now it has a single 300 Yam. HPDI on it . It is not a bracketed boat but an open transom model.
I cant imagine not being able to put any 500 to 600 lb motor on that boat , bracketed or open transom model.
I can also guarantee the op's boat was a dog with a single 175 on it. It must've had a 14 or 15 pitch prop on it to even plane off.
richie rich
Well-Known Member
That original engine weighs around 414lbs....a 225 Yamaha 4S will be 583lbs.....604 for a 250.....an HPDI 2S is only 475lbs......the Suzuki DF225 4S is 591lbs......thats 177lbs over the original designed weight!.....will it work, yes, will it sit lower in the water, yes, will you like the aft end sitting that low in the water??? I would float the boat and park your butt on top of the engine and see how low she sits....if the scuppers are half way above the waterline, you should be OK....if they are submerged with your extra weight, I would look at the HPDI or E-tec option.
shadow379
Well-Known Member
Offshore 24
I have the same boat, same year and everything. Its rated at 290hp..I am running a Johnson 200 ocean runner, and it ran out last time with a good chop at 38mph, with a 15x15 prop. I may get even more when I try my 14.25x19. but its plenty of power. I know the 4stroke would be heavier and not too sure about the performance, but am very interested in seeing how it works out for you.
I have the same boat, same year and everything. Its rated at 290hp..I am running a Johnson 200 ocean runner, and it ran out last time with a good chop at 38mph, with a 15x15 prop. I may get even more when I try my 14.25x19. but its plenty of power. I know the 4stroke would be heavier and not too sure about the performance, but am very interested in seeing how it works out for you.
catch22
Well-Known Member
Re: Offshore 24
Don't mean to split hairs here, but... if you check out the 1980 catalog - http://www.gradywhite.com/customer/catalogs/ you'll see the maximum hp rating is 280. They increased it to 300 in 1986.
14.25 x 19???... are you sure you didn't mean 14.25 x 15? Even with the smaller diameter... a 19 inch pitch is too much. I think you'll have a hard time getting on plane and once you do, you'll be lucky if you see 4500 rpm, (max). It may even cavitate, or slip on you. Sounds to me like your right where you should be, (topping out at thirty eight). And as long as it gets up on plane pretty easy.
I'm pretty sure my Seadrive had a 15 x 17. It labored getting up on plane, and was horrible with a heavy load, (4 people, full gas, etc). I probably should have been running the 15 x 15.
shadow379 said:I have the same boat, same year and everything. Its rated at 290hp..I am running a Johnson 200 ocean runner, and it ran out last time with a good chop at 38mph, with a 15x15 prop. I may get even more when I try my 14.25x19. but its plenty of power. I know the 4stroke would be heavier and not too sure about the performance, but am very interested in seeing how it works out for you.
Don't mean to split hairs here, but... if you check out the 1980 catalog - http://www.gradywhite.com/customer/catalogs/ you'll see the maximum hp rating is 280. They increased it to 300 in 1986.
14.25 x 19???... are you sure you didn't mean 14.25 x 15? Even with the smaller diameter... a 19 inch pitch is too much. I think you'll have a hard time getting on plane and once you do, you'll be lucky if you see 4500 rpm, (max). It may even cavitate, or slip on you. Sounds to me like your right where you should be, (topping out at thirty eight). And as long as it gets up on plane pretty easy.
I'm pretty sure my Seadrive had a 15 x 17. It labored getting up on plane, and was horrible with a heavy load, (4 people, full gas, etc). I probably should have been running the 15 x 15.
shadow379
Well-Known Member
offshore
In that case I may stay with the prop I have, the 19pitch came on the boat when I bought it, but never got a chance to run it due to a power-head failure. I kept the old prop. When I re-powered her the dealer put the 15x15 prop on, but I have to back down or it will over-rev. So thought the other prop may cure that...However it will jump out of the hole nearly as good as my ski boat...
In that case I may stay with the prop I have, the 19pitch came on the boat when I bought it, but never got a chance to run it due to a power-head failure. I kept the old prop. When I re-powered her the dealer put the 15x15 prop on, but I have to back down or it will over-rev. So thought the other prop may cure that...However it will jump out of the hole nearly as good as my ski boat...
catch22
Well-Known Member
Re: offshore
Idealy, you want to get as close as possible to the recomended max rpm's at full throttle. Throttle lever pegged, light to medium load, no tabs, engine trimmed up a bit and calm conditions. Again, thirty-eight mph sounds about right, but your rpm's should be around 5400-5600. That usually gives you the best, all-around performance and getting on plane easily should fall into place. If you have to back the rpm's down, then it sounds like you would benifit from more pitch... try a 17". Some dealers will let you try, (or experiment) with different sizes, until you find what's right, (of course your expected to make a purchase). If a 17" works out ok, keep the 15" as a spare and/or heavy load use.
Also... not sure how much adjusting they can do with a stainless prop, (assuming that's what you have) but, they might be able to reduce the pitch on your 19" prop. Best thing to do is talk with a dealer or prop shop.
shadow379 said:In that case I may stay with the prop I have, the 19pitch came on the boat when I bought it, but never got a chance to run it due to a power-head failure. I kept the old prop. When I re-powered her the dealer put the 15x15 prop on, but I have to back down or it will over-rev. So thought the other prop may cure that...However it will jump out of the hole nearly as good as my ski boat...
Idealy, you want to get as close as possible to the recomended max rpm's at full throttle. Throttle lever pegged, light to medium load, no tabs, engine trimmed up a bit and calm conditions. Again, thirty-eight mph sounds about right, but your rpm's should be around 5400-5600. That usually gives you the best, all-around performance and getting on plane easily should fall into place. If you have to back the rpm's down, then it sounds like you would benifit from more pitch... try a 17". Some dealers will let you try, (or experiment) with different sizes, until you find what's right, (of course your expected to make a purchase). If a 17" works out ok, keep the 15" as a spare and/or heavy load use.
Also... not sure how much adjusting they can do with a stainless prop, (assuming that's what you have) but, they might be able to reduce the pitch on your 19" prop. Best thing to do is talk with a dealer or prop shop.
shadow379
Well-Known Member
offshore prop
Thanks for the advice, haven't even thought to check with my prop shop both my props are stainless. The rpms will run around 6200 to 6300 WOT, but at 3400 its planing good at around 28 MPH and feels like the motor is barely working. These numbers are from GPS and include 100 gallons of fuel, three people, and 200lbs of dive gear.
Thanks for the advice, haven't even thought to check with my prop shop both my props are stainless. The rpms will run around 6200 to 6300 WOT, but at 3400 its planing good at around 28 MPH and feels like the motor is barely working. These numbers are from GPS and include 100 gallons of fuel, three people, and 200lbs of dive gear.