Boat rated for 50-85 hp

Hi. I have a 16' Starcraft bow rider. If its rated for 85 hp at the most would I be able to put a 90 hp on it. What would happen. Thanks.

Re: Boat rated for 50-85 hp

If all goes, well, you'd get just the right amount of air-in-your-hair!

Re: Boat rated for 50-85 hp

I'm thinking the difference wouldn't be anymore noticable than a good tune up, only because I just put an 80hp engine in place of a 60hp and the it's not all that noticable same RPM and top speed although I have yet to try it with a loaded boat, thats probably where the extra ponies will be felt, and my transom is rated for 70HP, I'm fairly reserved and not one to wring it out so I wouldn't be too concerned but thats just me.

Re: Boat rated for 50-85 hp

You can put a 300 HP on it ...... the only significant problem is LIABILITY

If there is ever an accident ....... you will be found liable.

Trust me this arguement has been repeated here quite often. HP is based on a USCG formula BUT (wait ther is more )........

An older 100 HP motor (as an example) was rated at the powerhead and really only provided 85-90 HP at the prop. New current motors are rated at the prop....... so a 100 hp motor is real 100 at the prop and possibly 115 at the powerhead.

It all sounds confusing (and I have not even added in weight of new 4 strokes yet ) but the standard iboats response is this........

We do not recommend or advise anyone to overpower a boat beyond the USCG capacity plate.

Re: Boat rated for 50-85 hp

Bob_VT said:

You can put a 300 HP on it ...... the only significant problem is LIABILITY

If there is ever an accident ....... you will be found liable.

Trust me this arguement has been repeated here quite often. HP is based on a USCG formula BUT (wait ther is more )........

An older 100 HP motor (as an example) was rated at the powerhead and really only provided 85-90 HP at the prop. New current motors are rated at the prop....... so a 100 hp motor is real 100 at the prop and possibly 115 at the powerhead.

It all sounds confusing (and I have not even added in weight of new 4 strokes yet ) but the standard iboats response is this........

We do not recommend or advise anyone to overpower a boat beyond the USCG capacity plate.

Click to expand...

What Bob said
Seems to be a lot of over power freeks lately ---
We may not (sadly) see some of them again

Re: Boat rated for 50-85 hp

I'm one of the overpowered freeks and incited some exciting discussion a few weeks ago for only going 10 hp over my hull rating. The cautions are valid. At least you're just thinking about it. I did it.

One the posts raises a question. If the boat is old enough to be based on hp rated at the power head, will a new motor rated at the prop be considered overpowered when both read the same hp on the motor housing? Something to think about if you want to split hairs.

Yes, consider the weight between the different motors. I think I compared a 40 hp merc to a 50 hp merc, 2-cycle a few years ago and found essentially weighing the same. The difference may have been the carberator, not the power head itself.

Go safe or go crazy.:redface: