Is a single 250 HP enough???

I posted this on your other post as well....
More then likely you would need to go 5" longer then your present set up. A 250 might be a little underpowered for you, you would probably cruise at 20-22mph and top out around 35 would be my guess. what about a 275hp Verado? Or a Suzuki 300hp? They have been performing fairly well and might give you another 2 or so mph on the cuise and top end and fuel numbers would be similar to any comparable 250 out there. I would say your performence would be similar to a single engine 268 islander due to weight. There were some with single 250's, but from what I've heard, the engines go a lot quicker with that engine package due to the heavy load applied to a single engine.

The Sailfish is not an Islander, more weight, more beam, and 4" shorter than Gradyfish's boat. Don't don't do the single 250 unless you want to be unahppy and kill a motor or never want to plane. If you're bent on a single, 300 HP MIN and 30" shaft.

I would look into the Suzuki 300

I wonder why anyone is recommending a 4 stroke single, when even the 300 HPDI was never advised previously, a higher torque engine than the Fs (except v8) or Zuks. Even if the guy doesn't care about top speed, he needs to climb out of the hole.

The 30 in. lower unit definitely.

I talked to a person who put a 250 Opti on his Trophy Pro "same hull but less weight" and he said it was a big mistake.

Now I would love to see someone try a Yamaha 350 on one of our hulls and see how that would do? Not me though I'm not that brave. :cry:

Yamaha catalog shows the F350 on a Parker single bracket, no problem for a bracket 25 ft Grady - need snew bracket though.

Would't mount it on a transom, unless plated with one 1/2 in. thick stainless plate on either side.

The F350 is so heavy at 822lbs, it wouldn't benefit a 255 sailfish. your best bet would be a 300 Verado for weight to HP and the numbers the engine itself has been producing, or a Verado 350SCI might be nice also at 667lbs, but might kill your pockets since it is a race engine. I still think a single is a mistake on a boat that size and weight. If you want more economical power plants and do not care about speed, and you want to go to suzuki's as you mention, a pair of twin suzuki 140's might be a nice match for that boat. A single 250 would be a huge mistake and the boat would have a tough time ever selling if you decided to move on to something else down the road, you would almost end up giving it away.

A single F350 is less weight than twin V6 anything 200/225.

Zuke makes 175's that are 485#'s and would have a chance to be effective. I think someone put a pair of them on a Trophy Pro or Sailfish a while back.

The guy wants a single, the boat is rated for twin 200s max, probably never left the dealer with a single.

Boat was never offered with a single, at the time big outboards were not available, although I'm not sure todays big outboards would be a great match, a 300+hp engine would work but would be far from my top choice, and boy will that boat have a tough time ever selling if he does not like it or looks to upgrade.

I dunno, 350 might look pretty nice on that boat.

The 350 would be more work than it's worth. It has a better chance to fit since he doesn't have a bracket but bracing is definitely needed and I'd get Grady's blessing before dumping that much money.

When you go the the single you also loose a lot of manuverability.

Also, the 300 and 350 cowling's are taller then smaller engines. Even with the fold down transom, it may still hit the cowling when fully tilted, there is a raised lip where the well folds up and down, check clearance here. Regardless, going from twins to singles will need some work to the transom. You are placing more weight over a smaller area, instead of spreading it out, you can't just plug up the old holes and mount a new engine, that would be a mistake that might be costly. If I were ever to consider a 25ft boat with a single, it would be a 350, I would always regret a 300 but it looks like he is bent on going to a single and it is not my boat. I think I would buy used twins or new ones over a big single on that hull. I agree with Bob, 30in shaft would be my recommendation, but check with your local dealer. A 25 inch will likely have trouble in rough conditions and could be a nightmare.

Evinrude just came out with a new 300HP E-TEC, if interested in a 2 stroke.

The E-Tec is lighter in weight then the Suzuki, but has a smaller displacement, going to a single means you want torque. Usually a larger displacement engine is better for this, but it is not always true. Have not heard many reports about the 300 E-TEC yet, but that might be an interesting engine choice, I still say twins are better but the light weight of an E-TEC might benefit this situation.

My 2 cents.

I have seen two 25ft Grady White's with single outboards. They were both Trophy Pro's from the mid 1980s.

One had a late 1990s 225hp 3.0liter EFI Mercury no hard top.

The other had a 2005 250hp Suzuki 4 stroke with a hard top.

The boats both looked fine in the water with set up and I am sure had a cruise of mid 20mphs with top end in low 30's.

Having said that, I would only rig a single if you planned on keeping the boat for a while (resale no factor) and do not mind a slow cruise.

The engines were available in the 1980 and 1990s and I am sure that Grady White did try a single on these boats. They had the 300hp V8 3.6liter and 4.0liter Evinrude/Johnsons in the 1980s and 1990s and also the 3.4liter Mercury 275/300hp engines also. I suspect that the only reason that they did not offer them was because it would not make sense. I doubt the demand for an offshore boat with a single would have been too high. Now that the reliablity of the OB is better and the fuel crunch, I suspect the demand is better.

I suspect that the performance is fine if you can live with a 23-24mph cruise. About a year ago, someone repowered a Sailfish 25 with a single 250hp Yamaha 4 stroke and was unhappy with the performance and did not like having to cruise at a higher RPM


FYI My secret little project (still working on it) is a 25ft FBSF Bertram 1967 Mark II (Solid Glass). I knotched the transom and installed a tired SINGLE 225hp Optimax and get a 25mph cruise and 39mph top end. Its all in the proping. I couldnt be happier.

I have a 1995 Islander 26 with a 225 original Mercury. The motor pushes the boat just fine. In todays fuel environment, single engines are the way to go if possible. Grady says that this was a good option for this boat in 1995.

If I am guessing correctly, you have an pair of old Suzuki's? The best and cheapest way to go is with a new pair of Suzuki's. It's not just the cost of the engine(s) but the cost of rigging. Old holes need to be filled and new ones drilled. Just the thought of putting holes in my boat makes my knees weak :shock: . Then there is are the controls, not to mention the resale difference betweeen the single/dual engines. I have always perferred the redundancy of 2 engines. Still bothers me that I can't install twins on my 208 Adventure. Twin 115's would be nice. :wink: