300hp on a 250hp spec'd boat?

[Salmon_Slayer]

I have the chance to purchase a new yamaha F300 25" for less than you can get a new F250, my boat is technically only spec'd for max 250hp for this year but the yamaha 300/250 is the same, same weight & powerhead just different tuning. I don't plan to run 91 octane for the 300hp anyway, so it will be "derated" with regular 87 octane...should I do it? I don't really see any disadvantages?

Going on a 1999 Seafarer 228, price of the new F300 is $23,500 + install

 

[Halfhitch]

If your transom is sound, I wouldn't hesitate were I, you.

 

[Fishermanbb]

There are only 3 reasons I can think of not to go over rated horsepower:

1. Too much weight for the transom/waterline (Etc) - NOT the case here

2. Too much HP for the hull (Yes, that is a real thing) can make the hull unstable at high speed - NOT the case here

3. IF you have an accident AND your insurance company can PROVE that the additional HP over the rating was a contributing factor, - they can refuse to honor your claim. Also, if someone is injured they can theoretically sue you for negligence IF the extra HP can be PROVEN to be the cause.

You’re fine. Hang it and go!

 

[FREEDOM!!!]

There are only 3 reasons I can think of not to go over rated horsepower:

1. Too much weight for the transom/waterline (Etc) - NOT the case here

2. Too much HP for the hull (Yes, that is a real thing) can make the hull unstable at high speed - NOT the case here

3. IF you have an accident AND your insurance company can PROVE that the additional HP over the rating was a contributing factor, - they can refuse to honor your claim. Also, if someone is injured they can theoretically sue you for negligence IF the extra HP can be PROVEN to be the cause.

You’re fine. Hang it and go!

#3 would be my only concern....especially from Yamaha. A new engine has 3 year warranty. If there is an issue that requires warranty repair I wonder how Yamaha would react if they found out the engine was not intended for that boat.

 

[seasick]

Personally I wouldn't exceed the stated max HP purely for liability issues. My insurance company asks what motor is on my boats and I wouldn't lie about the specs. I am pretty sure that if you ask your insurance company about over-powering, they wouldn't approve.
Regardless of what others have said, the 300 produces more power than the 250. I can't say for certain if that will be an issue.
I am also curious what the 300 is less costly that a 250. Is it a supply and demand issue.

 

[JJF]

I agree with the insurance/legal/liability part of this. However, you could try a specialty insurer. I think WOZENCRAFTINSURANCE might be an option.

In addition top the above, I will add another concern: resale - it could be very difficult to sell a boat with a motor that exceeds the max HP rating.

 

[Halfhitch]

I will add another concern: resale - it could be very difficult to sell a boat with a motor that exceeds the max HP rating.

Not in Florida.
https://www.myboatlife.com/2021/02/too-much-power-5-or-6-outboard-engines-boat-trend.html

 

[JJF]

Not in Florida.
https://www.myboatlife.com/2021/02/too-much-power-5-or-6-outboard-engines-boat-trend.html

I think there is a big difference between lots of HP approved by the builder versus exceeding the builder's specs.

 

[glacierbaze]

AFAIK, capacity plates are only required on boats 20 feet, or less. I don't recall one on my 2000 SF228. Where are you getting the rating from? Was 300 even available for your boat?
Many people do it, get a written rider from your insurance company, not your local agent.

 

[wrxhoon]

Insurance will be the main reason not to exceed the max HP. The other thing to consider is strength, this boat was made to take 250 HP max . On post 2012 228's the rear bracket and swim platform are all aluminum welded together so it is stronger. At the same time GW uprated them to 300 HP.
If I was you I would stick with the 250 HP.