Horsepower Question

[flipnello]

Hey Everyone,

I picked up a boat at the end of last season and didn't realize until a few weeks later that the motor on it was 25hp too high. The boat is a 1980 Sylvan 17' fiberglass deck boat, and is rated for a max of 150hp. The motor is a 1983 Evinrude 175hp. The motor runs like a top and I'm very happy with it, so would like to just leave it as is.

In researching the issue myself, I have determined that weight shouldn't be an issue, as a similar year 150hp would only weigh slightly less than what I have on there now.

Someone mentioned to me that back in the early 80's horsepower was rated differently (at the crankshaft as opposed to driveshaft maybe?), and that a 175hp from 83 is actually similar to something smaller now-a-days.

So... that, along with assuming some power loss due to age, possibly some small compression loss, etc., does anyone have any advice or feedback on this situation?

I realize there is also the legal side of things - but figured if the concensus was that this situation is fine from every other perspective, I could either paint the engine cover or order new decals or something...

Thanks in advance for any thoughts.

 

[Texasmark]

Re: Horsepower Question

Big guns will know (and respond to my comment....you can bet on it....but that's the way is should be) but I think you are 1 year before OMC went to prop rating (1984 is the number I have seen). I just ran the 15% rule and if you take 85% of your 175 you are at 148.75 which meets the criteria. As far as legality, I would be willing to argue my case, if I knew and could prove that the current engine was power head (brake hp) rated, that it produces less than a current 150 would produce and therefore meets the BIA certification requirement.

 

[steelespike]

Re: Horsepower Question

I think the smart thing is to get the correct hp.You forgot to include the boat may be somewhat
comprimised from age. Then as you mention there are the legal issues if some sort of incident/accident occurs.
and insurance may not want to insure it for the same reasons.
I'm probably being picky.
Just locate a nice 150 and sell the 175.but keep it on the boat for test drives.
One advantage for the 150 is it will use about 2.5 gallons less per hour at wot.

 

[Home Cookin']

Re: Horsepower Question

in some places it's illegal to paint over the numbers--that includes camoflage painting a motor for hunting. But that's mainly to look for too-big motors in <10 HP waters.

There's a lot bigger difference between 9.5 and 25 than 150 and 175, and it will be hard to replace a good running early 80's motor with another that doesn't have problems. You didn't hear it from me but I'd be inclined to live with it, be careful, and don't get in any wrecks at more than 3/4 throttle.

 

[Lyle29464]

Re: Horsepower Question

decals are cheap

 

[F_R]

Re: Horsepower Question

If you cause an accident for any reason and have that boat overpowered, you can bet you are going to get sued and possibly lose your car, bank account, retirement, boat ,wife, dog, and anything else you have. If you paint or modify it somehow with intent to deceive, that makes it even more likely that you will lose the lawsuit. If I were on the jury, I's say that intentional deceit is even worse than negligence.

Disclaimer: I'm not a lawyer.

EDIT: You could also do some prison time on a homicide charge. Still not a lawyer.