MAX HP Rating

[redogman67]

I have a 1973 14' forester trihull that says the max hp motor is 30hp. I have a 25 hp on it now but lower unit is done for. So I have an opportunity to buy a 1979 johnson 35 hp with controls for $500. Do you think going 5 over the max horesepower would cause much of a problem, I cant see how it would but, i am no expert . and does it seem like a decent deal?

[BoxMN]

If I am not mistaken, the 25, 30 and 35 hp johnson/rude motors of that vintage are about all the same. I have a '96 25hp rude, and it is basically the same as the 35 of the older motors. Rated at the prop, that 35 is probably less power than a 25 of today, or pretty close.

That said, they have the ratings for a reason, and I could not recommend going over it... but.... realistically there is no difference... IMHO...

[broken_line]

im not a expert but i had a 25hp chrystler on my 13 foot duck boat and thats only rated for 10hp..i didnt have any problems with it except the bow always wanted to rise when you canned it.

[redogman67]

Yeah I can't really see how it could be too dramatic of a difference, but just wanted some more opinions because its an older boat I am a bit worried about the transom strength but I bet they figured in some room for error when they rated it 30hp, I doubt they would rate it at the very edge of what it could handle safely. I think I will prob go for it if it turns out to be decent(haven't seen it yet, but told its clean)

[Ralph Wiggum]

Be aware that it's illegal and you'll get a ticket if they ever check you.

[redogman67]

one thing I forgot to ask, the guy said its coming off of a 16' boat so I am assuming the spot that the controls were mounted on his boat will be farther of a distance from the motor than would be on my 14' boat. In other words I am assuming the cables will be a bit longer than needed. This shouldn't effect performance of the cables will it? I am thinking that because the cable is fixed in place at the controls and at the motor the amount of slack in between shouldn't matter(I am not expecting to have a crazy amount of extra cable, just that it will prob slightly loop towards the floor in the middle) SO what I am asking is, the cables don't have to be pulled tight from motor to controls to work right?

[redogman67]

@ Ralph,

Yeah I am aware of this but I don't really feel like its making it dangerous to me or others so I am willing to risk a ticket, especially because I never really see the dnr. And I can always play dumb if all else fails haha. Appreciate your concern though

[BobT]

Playing dumb isn't a valid defense but your risk is yours to a point....if you are alone in the boat.

In reality it goes without saying that the boat is probably designed to handle a bit more than the 30hp rating and you may be able to get by using the 35 on there but ratings are there for a reason. It's a safety net and not to be an inconvenience. The weight, length, width, displacement, and hull design are all part of the calculation that determines a boat's rating for load and horsepower. Once you exceed that rating you are increasing your risk beyond a reasonable level.

There will be those that will say, my boat is rated for XX and use a YYhp rating but then ask yourself this question.

If I have been backing out of my driveway onto a busy street every morning for the past year and I have never had to wait for a car, it it therefore safe to assume that there will be no car and I can now do it without looking first?

Bob

[marine_man]

If you are ever checked or ever in an accident you will have a way higher likelihood of being found negligent in the incident because your motor is over the rating for your boat.

While I agree a lot of things have changed over the years, sticking to the motor hp rating as posted on your boat is still a good thing to do, especially if you're re-powering. Keep looking.

marine_man

[boatfixer]

I have to agree with Ralph, MM and Bob, Dont exceed the max.

[broken_line]

is it illegal if the tin plate that says all the stufff about the boat is gone??? mine fell off 2 years ago...

[marine_man]

The coast guard still has record of what a boat was rated for. While it may be a slightly gray area, I suspect you'd still be negligent.

marine_man

[broken_line]

so a guy wont get a ticket if im checked and the plate si missing??

[marine_man]

I don't know for sure on that. You'd have to check with the coast guard.

marine_man