Swapping out F250 Yamaha for BT350 Honda

[Dleigh18]

I have a 2007 GW 257 Advance and the YAMAHA-ROT got me on my Yamaha F250 with 578hours. I am having the dealer swap out this motor for a brand new 2026 Honda bt350hp! I cannot wait and the deal Honda is doing for repower is unbeleivable! Plus a 5yr warranty! I could not pass it up. Wanted a Mercury 300hp but it was going to be 25k high, double the price...... So i dropped it off May 2nd and hope to get back soon and i will post some info on speed, GPH and thoughts.....

Anyone do this yet??

 

[DennisG01]

Granted, Honda isn't as "new" and advanced as the Merc, but... $25K difference?!?!!? Holy cow! That' s GIGANTIC difference and more than makes up for any "betterness" of the Merc! Is that word?

Is something going on with Honda that they're trying to liquidate their engines? That's an amazing price.

 

[Dleigh18]

Granted, Honda isn't as "new" and advanced as the Merc, but... $25K difference?!?!!? Holy cow! That' s GIGANTIC difference and more than makes up for any "betterness" of the Merc! Is that word?

Is something going on with Honda that they're trying to liquidate their engines? That's an amazing price.

they are setting the stage to make the 350hp block 500hp+ and getting as many 350's out there so when they introduce a 500hp+ it is not a shocker it will be a proven motor/Block

 

[Mustang65fbk]

As mentioned in another thread... it seems very odd that they're discounting the Honda 350 by like $10k+, as it's essentially a brand new design that they've come out with only in the last couple of years. It almost seems like they're going to go with a different design or they aren't selling very well, or something similar. I think that I personally would go with the Suzuki DF350A if I were in the same boat as you are, pun intended. It's about 30 lbs lighter, can oftentimes be found in that $20k-$25k price range as well, it also comes with a standard 5 year warranty and is a 6 cylinder vs an 8 cylinder... so it'll likely do a bit better on fuel economy. Sounds as though you're happy with your selection/purchase, good luck with the repower.

 

[Dleigh18]

I will take a V8 over the v6 anyday. The v8 has more torque, can run at lower RPM and from what they are saying we shoudl be close to 3miles to the gallon! Honda is setting the stage for 500+HP but needs the people to love the 350hp first so they are getting them out there!

Any pics of the mustang? I own a 66FBK mustang. All original california car. Been in the family since 1970....lol

 

[Mustang65fbk]

I will take a V8 over the v6 anyday. The v8 has more torque, can run at lower RPM and from what they are saying we shoudl be close to 3miles to the gallon! Honda is setting the stage for 500+HP but needs the people to love the 350hp first so they are getting them out there!

Any pics of the mustang? I own a 66FBK mustang. All original california car. Been in the family since 1970....lol

It's interesting because people keep talking about torque numbers and so forth, yet I don't think any outboard manufacturer actually posts their numbers for ft/lbs of torque. I imagine that the Honda 350 likely has more torque considering that it's a v8 as opposed to the Suzuki considering that it's a v6, but yeah... not sure how to prove that at this time. It is also another great thing about the Suzuki in that it does run a lower gear ratio, so that it can use considerably larger diameter props and have a good deal of low end torque to them. Might not exactly be to the same level as a v8 outboard, but imo I'd sacrifice a few ft/lbs worth of torque for better fuel economy, especially if you need as good of fuel economy as possible for long distance trips, etc.

I do have a few pictures of the mustang, she's a 1965 fastback that the previous owner cut the rear vents out of and added the Shelby plexiglass windows. So, it's kind of more of a "Shelby look alike". I've had her since I was 15, so just over 25 years now, put a 351w crate motor with aluminum heads in her with 450 hp, 5 spd transmission, side exit exhaust, four wheel disc brakes, Foose 17" wheels, Ford 9" with 3.50 gears, updated suspension and so forth. I took a pretty cool picture at a car show up here years ago with the Paul Allen collection at Paine Field. Was really cool seeing and walking through a B-29 as well as several other WWII planes, a P-51 Mustang, a B-24, etc.

 

[Dleigh18]

they are claiming on my 25cc 3 miles to the gallon! Not sure you can get better than that. They use a 2 stage/step cam for lower end and higher speeds to get better GPH. And unlike the Suzuki it runs on 87 octane!

Beautiful car. Here is ours.

 

[DennisG01]

I will take a V8 over the v6 anyday. The v8 has more torque, can run at lower RPM and from what they are saying we shoudl be close to 3miles to the gallon! Honda is setting the stage for 500+HP but needs the people to love the 350hp first so they are getting them out there!

I couldn't agree with you more - that's a big boy engine, for sure. I wasn't (still am not) overly famliar with Hondas of that size, but I looked it up and it's a solid 5 liters of power. I'll take that every day of the week over a V6. 'Course, that Merc V10 is a VERY cool engine... bigger, more power and decently lighter... but then we're back to the cost and it's not even close to what you got.

You got a heck of engine going on your boat!

 

[Mustang65fbk]

they are claiming on my 25cc 3 miles to the gallon! Not sure you can get better than that. They use a 2 stage/step cam for lower end and higher speeds to get better GPH. And unlike the Suzuki it runs on 87 octane!

Beautiful car. Here is ours.

I mean... I'd hope that you'd be getting above 3 mpg, as I just saw a performance data sheet on a 257 Advance with a single F250 on it, and the optimum cruise was @ 4k rpm, burning 9.1 gph of fuel and getting 3.01 mpg. If that boat, which is likely quite a bit underpowered, can do it then I'd again hope that your setup with an extra 100 hp should be able to do it no problem. I know that the 228 Seafarer has a dry weight of over 500 lbs less than the 257 Advance, and the sweet spot on it seems to be the F250, and in later years they even increased the maximum horsepower on it up to 300 hp. I'd be willing to bet that F250 was working pretty hard, and was a bit underpowered as the top speed was only 42.7 mph. I guess we'll just have to wait and see what your numbers are on your boat when you launch it. Congrats on the repower and good luck.

 

[Dleigh18]

I mean... I'd hope that you'd be getting above 3 mpg, as I just saw a performance data sheet on a 257 Advance with a single F250 on it, and the optimum cruise was @ 4k rpm, burning 9.1 gph of fuel and getting 3.01 mpg. If that boat, which is likely quite a bit underpowered, can do it then I'd again hope that your setup with an extra 100 hp should be able to do it no problem. I know that the 228 Seafarer has a dry weight of over 500 lbs less than the 257 Advance, and the sweet spot on it seems to be the F250, and in later years they even increased the maximum horsepower on it up to 300 hp. I'd be willing to bet that F250 was working pretty hard, and was a bit underpowered as the top speed was only 42.7 mph. I guess we'll just have to wait and see what your numbers are on your boat when you launch it. Congrats on the repower and good luck.

That is what i had on it and trust me we never saw 3MPG. (4krpm 9.1mpg at what speed? ) i can run at 3 knots and get 7miles to the gallon. But hell thats no fun!

I would run that boat at 5,000rpm to keep it at 29mph buring 13.5GPH. thats like 1.9-2,1 but 5000 rpm is "hard" on that motor in my opinion. At 4,000 it was 21mph which blows for a CC.

This is why i went with the V8 i can run this one i hope at 4000 and be doing 30+.

 

[Mustang65fbk]

That is what i had on it and trust me we never saw 3MPG. (4krpm 9.1mpg at what speed? ) i can run at 3 knots and get 7miles to the gallon. But hell thats no fun!

I would run that boat at 5,000rpm to keep it at 29mph buring 13.5GPH. thats like 1.9-2,1 but 5000 rpm is "hard" on that motor in my opinion. At 4,000 it was 21mph which blows for a CC.

This is why i went with the V8 i can run this one i hope at 4000 and be doing 30+.

It's in the performance data sheet that I attached above... 27.4 mph

 

[Dleigh18]

It's in the performance data sheet that I attached above... 27.4 mph

Well, you can believe that or me. That might be day one at the factory! I put 350+hours on the boat. 5000rpm is 29-30mph. buring 13.1gph. Show me a report for the 350 Yamaha and i will compare that next weekend to the facts of a HONDA

 

[Mustang65fbk]

Well, you can believe that or me. That might be day one at the factory! I put 350+hours on the boat. 5000rpm is 29-30mph. buring 13.1gph. Show me a report for the 350 Yamaha and i will compare that next weekend to the facts of a HONDA

I don't have that information and can't find anything about it on Google, so it's a little bit difficult to compare. There is a performance data sheet for a 251 Coastal Explorer with a single F300 available on the Grady White website, it has a heavier dry weight compared to your boat and slightly less than a brand new 257 Fisherman, though they're obviously two different boats. That being said, with the F300 the boat still has an optimum cruise @ 3,300 rpm while going 27.1 mph, burning 7.4 gph of fuel and getting 3.66 mpg. Most of the newer 257 Fisherman boats have twins on them, including the one on the Grady White website, so it's again rather difficult to find that information or compare boats. You could always email or call Grady White and ask them for a performance data sheet of a 257 Advance with a single F350 on it? I'm not saying either person's numbers are incorrect, I don't imagine that Grady White is lying about their numbers, but I'm sure that they likely use 25 gallons or less of fuel, do the tests in perfect conditions with next to no additional weight onboard in order to get the best numbers possible. It's also possible that you had the wrong size/pitch of prop on your boat and that's why you were seeing lower numbers on your previous outboard as you mentioned you were at 5k rpm, 29-30 mph and 13.1 gph whereas the GW performance bulletin has their boat at 5k rpm while going 35.3 mph. Or as mentioned, if you were consistently running with 4-5+ people on board, bait tanks, hundreds of additional pounds of gear and so forth, the numbers will likely be quite a bit different than perfect or optimal numbers in perfect or optimal conditions. As you mentioned, you're happy with the repower choice, we'll just have to wait and see how the numbers compare to when you launch the boat next weekend.

 

[Dleigh18]

I don't have that information and can't find anything about it on Google, so it's a little bit difficult to compare. There is a performance data sheet for a 251 Coastal Explorer with a single F300 available on the Grady White website, it has a heavier dry weight compared to your boat and slightly less than a brand new 257 Fisherman, though they're obviously two different boats. That being said, with the F300 the boat still has an optimum cruise @ 3,300 rpm while going 27.1 mph, burning 7.4 gph of fuel and getting 3.66 mpg. Most of the newer 257 Fisherman boats have twins on them, including the one on the Grady White website, so it's again rather difficult to find that information or compare boats. You could always email or call Grady White and ask them for a performance data sheet of a 257 Advance with a single F350 on it? I'm not saying either person's numbers are incorrect, I don't imagine that Grady White is lying about their numbers, but I'm sure that they likely use 25 gallons or less of fuel, do the tests in perfect conditions with next to no additional weight onboard in order to get the best numbers possible. It's also possible that you had the wrong size/pitch of prop on your boat and that's why you were seeing lower numbers on your previous outboard as you mentioned you were at 5k rpm, 29-30 mph and 13.1 gph whereas the GW performance bulletin has their boat at 5k rpm while going 35.3 mph. Or as mentioned, if you were consistently running with 4-5+ people on board, bait tanks, hundreds of additional pounds of gear and so forth, the numbers will likely be quite a bit different than perfect or optimal numbers in perfect or optimal conditions. As you mentioned, we'll just have to wait and see how the numbers compare to when you launch the boat next weekend.

usually had 2-4 ppl and at min 1/2 tanks.... The prop i had was the factory stainless size. I cant wait to fill everyone in on the new numbers and the new pics...... Very excited! The f300 at 3300 ( that is jogging) at 7.4gph wow!!! I cant wait to report the numbers with pics....lol