Hull max hp rating

[vtwin4life]

Excuse my ignorance here - but how do you guys run so much motor on your boats. My 86 sportfire says it's rated for max 140hp. Obviously there's a lot here I don't know.

 

[83PREDICTOR]

I belive HP ratings are concluded by a length / width math equation. Not necessarily the the strength of the boat.

 

[wizard8575]

lol what max hp I dont know what you talking about

not to many people actually follow those things from what I have seen.

 

[Turbot-bird]

I dont even remember seeing a max hp on the diplomat

 

[Blizz]

I believe for CG and insurance puposes they have to put on a rating. It's usually not strongly enforced buy the water police (whoever they are in your area) insurance is a little stiffer. And as long as you don't get in an accident most don't catch much flack.

 

[vtwin4life]

I believe for CG and insurance puposes they have to put on a rating. It's usually not strongly enforced buy the water police (whoever they are in your area) insurance is a little stiffer. And as long as you don't get in an accident most don't catch much flack.

I'm not really worried as much about the legal or insurance aspect, but more with structural integrity. I figured the max hp ratings had to do with how much weight or raw force the boat or transom could handle.

I'm totally new to all this big hp stuff. I'm more used to smaller aluminum boats with 40hp mercs that do 30mph, or pontoon boats that do 10 beers an hour.

 

[Blizz]

I've seen stock 13 14 and 15ft boats with V-6 mercs on them and punished while driven and they held up. I would not recommend this on a reg bases but pretty much any Checkmate can handle V-6 power fromo the factory.

 

[topher312]

the only thing that you really have to be careful with is the coast guard. they are known to give heavy fines for that. if they happen to stop you for a random vessel examination they can fine you. an easl way around this that i have found is to put the decals off of a smaller hp motor on your engine cover. my boat is rated for 200 max but has a 235hp evinrude sittin on the transom. i put 150 decals on my engine cover and no one has said anything about it. except that they want their money back for losing against a 150 lol

 

[Mark]

The Sportfire has a very well constructed transom. As long as it has not been compromsed by water and rot it will easily hold a V6. In fact, the earlier models were rated for a 150 before they started measuring propshaft not engine HP in the mid 80's.
A V6 135 Merc is a very good choice for the hull and still perfectly legal.