Is It Too Much Horsepower????

Fiberformboatowner · Mar 31, 2013

I have a 200 hp outboard motor hooked up to my 19ft boat and I noticed that on the metal manufactures plate it says 150hp max is that going to cause any problems?

bob johnson · Mar 31, 2013

Re: Is It Too Much Horsepower????

in some states , thats illegal. In most there is no legal issue.....someone along the line has engineered that boat to with stand the forces that a 150 hp can affect onto it...and to some measure the weight.....i am sure there is a huge safety margin. You may never incure a single issue, you may start to stree the transom... so much depends on the make of the boat and how you use it, especially how you trailer it....what year and make si the boat...and is the motor a 4 stroke or a 2 stroke?...bob

Fiberformboatowner · Mar 31, 2013

Re: Is It Too Much Horsepower????

bob johnson said:
in some states , thats illegal. In most there is no legal issue.....someone along the line has engineered that boat to with stand the forces that a 150 hp can affect onto it...and to some measure the weight.....i am sure there is a huge safety margin. You may never incure a single issue, you may start to stree the transom... so much depends on the make of the boat and how you use it, especially how you trailer it....what year and make si the boat...and is the motor a 4 stroke or a 2 stroke?...bob

its a 1976 fiberform ive had the hardest time trying to cross reference what type of model it is but it looks like it was mad stock the motor cover has the same color scheme of the boat its a 2 stroke v6 Johnson I bought the boat last year for a steal, 300 dollars guy said it grinded a little bit going into forward gear when he last drove it so he rowed it back to shore and he let it sit for two years in his driveway uncovered with as bad as snow as we get here the floor was thrashed from the weather I actually got all the floor ripped up and in the process of putting new wood in..... anyways just replaced the water pump and a few other parts and hoping to hit the water soon

Crosbyman · Mar 31, 2013

Re: Is It Too Much Horsepower????

better clear it with your insurance Co. ....(liabilities may be yours if the added risk is not divulged before hitting the water !!)

emdsapmgr · Apr 1, 2013

Re: Is It Too Much Horsepower????

The metal tag rating back in 1976 was probably a manufacturer tag. The boat's design engineers determined what the hull could withstand. Somewhere in the early 80's (?) the US Coast Guard got into hp ratings. Their ratings trumped the manufacturer's ratings. The CG ratings were determined by a strict formula of length times width. Certainly not very scientific, and often not accurate. Today no boat dealer will install a larger hp engine than that rated on the plate, whether it's a manufacturer plate or CG plate. While not maybe illegal, there is a lot of liability should the boat ever become involved in an accident. So, while the boat may withstand the extra hp, you may not be able to insure it. As the owner, you need to assess the risk involved.

bob johnson · Apr 1, 2013

Re: Is It Too Much Horsepower????

emdsapmgr said:
The metal tag rating back in 1976 was probably a manufacturer tag. The boat's design engineers determined what the hull could withstand. Somewhere in the early 80's (?) the US Coast Guard got into hp ratings. Their ratings trumped the manufacturer's ratings. The CG ratings were determined by a strict formula of length times width. Certainly not very scientific, and often not accurate. Today no boat dealer will install a larger hp engine than that rated on the plate, whether it's a manufacturer plate or CG plate. While not maybe illegal, there is a lot of liability should the boat ever become involved in an accident. So, while the boat may withstand the extra hp, you may not be able to insure it. As the owner, you need to assess the risk involved.

company "A" has a 19 ft fiberglass column steered runabout, rated for 90 hp max according to the coast guard tag, company "B" has a 19ft fiberglas column steered bassboat that is rated for 250 hp............tell me how they pull that off when there is a formula that is based on the size of the boat...

bob

JB · Apr 1, 2013

Re: Is It Too Much Horsepower????

Length and width are only two of many factors that engineers consider in rating safe HP for a boat, Bob. That Bassrocket is immensely more rigid that the runabout.

I consider it a "Hey, Bubba, hold my beer and watch this." sort of risk to overpower a new boat and purely dangerous to overpower one that is older and may have some secret rot in places that are critical to the strength of the hull.

H20Rat · Apr 1, 2013

Re: Is It Too Much Horsepower????

The iboats crowd is going to jump all over you, but it is not 'illegal' to overpower a boat, much like it isn't illegal to add more horsepower to your car... Also, insurance generally doesn't care what the plate in the boat says. (which, depending on your state laws, may or may not even be required!) Worked in insurance for many years, not once did the mfg rating EVER come into play. (not saying motor size wasn't important, as there was a certain size to hp ratio that more or less become uninsurable. It was meant more for the muscle PWC's, guys running 250+hp in a pwc 10 feet long. Motor size also affects rates for regular non-pwc boats.

Common sense is far more important... Is the transom structurally sound? A modern heavy 4 cylinder 150hp is going to weigh more than a 200 hp 2 stroke from when the boat was made, so that is where common sense comes in.

Texasmark · Apr 1, 2013

Re: Is It Too Much Horsepower????

My insurance co wants to know what the BIA rating, which takes into account more than LxW, and the actual hp on the boat. If you run over someone with your rocket, the prosecuting attorney will be interested in those numbers too!!!!

Mark

BonairII · Apr 1, 2013

Re: Is It Too Much Horsepower????

I would've very careful going that much over the boats max rating. I would be one thing to do it if the boat was brand new. But in your case the boat is 35+ years old. Doubtful that the transom is as strong as it used to be.

Fiberformboatowner · Apr 1, 2013

Re: Is It Too Much Horsepower????

Thanks for the responce everybody everything seem structurely sound with the transom but could 50 extra hp really cause me that much greive ? and with the insurance guys im lost at this point in time every number n the boat ive tried to cross reference even on the plate with the max hp on it I cant find anything on this boat any reason to that?

Silvertip · Apr 1, 2013

Re: Is It Too Much Horsepower????

IF the capacity plate says 150 HP max then that's the max. You can certainly install a 200 but this is where you run the risk. I would bet the boat can take the extra 50 HP. But have an "incident", your fault or not, and insurance companies and lawyers will certainly be involved. If overpowered you can bet your boat and lots of your other stuff will belong to the victims. If you don't tell the insurance company then they may just deny a claim leaving you hanging by your wallet. In my view this is like so many other things in life that are simply not worth the risk. Put another way, if you do have an "incident" you had better hope it does not involve me.

spdracr39 · Apr 1, 2013

Re: Is It Too Much Horsepower????

Your half ton pickup is rated to pull 6000 lbs but you can pull 10000 if you want to. Is it safe? Maybe depending on your experience, the condition of your equipment, and the terrain. Should you do it? That's based on your comfort level. Just the fact that your asking tells me either your not comfortable with it or you just don't know. Either way I would not do it but it is 100% your decision.

Fiberformboatowner · Apr 1, 2013

Re: Is It Too Much Horsepower????

Sweet thanks for the info guys good news i live in the western part of the us so I doubt you'll run into me or vice versa

BobGinCO · Apr 1, 2013

Re: Is It Too Much Horsepower????

Fiberformboatowner said:
Sweet thanks for the info guys good news i live in the western part of the us so I doubt you'll run into me or vice versa

That's really not the issue.

Looks like you're just asking us to tell you "no problem bro" and since we're NOT telling you that, you're going to do what you wanted anyway, even if it's NOT a good idea. Your risk, your consequences.

BobGinCO · Apr 1, 2013

Re: Is It Too Much Horsepower????

Bubba1235 said:
Umm, isn't that what every boat owner does? I know I do. Opinions and feedback are nice and all but we do what we want.

Interesting point. I guess if I was asking people's opinions, and they all said "that's a bad idea, and here's why", I might rethink my idea. I would certainly be open to the idea of NOT doing it, under those circumstances. What's the point of asking, if you're not going to listen to the answers?

BobGinCO · Apr 1, 2013

Re: Is It Too Much Horsepower????

Bubba1235 said:
Truth is, very few people really run WOT very often with that big an engine, Outboard or I/O. Now if he happens to go out one day and its a perfect 75 degrees, water is like glass and he's got a 5 mile straight run, well then he might push a little harder and it should be fine. I know if I had an O/B that ran and worked well on the boat I would not be in any hurry to spend the money changing it.

No question that the motor you already own is the one you're likely to use! I make sure to run my boat at WOT every time I take her out, at least for a while, just to maintain engine health. Most of us can't afford to run WOT all the time!!! If I had a 200 instead of a 115, I would certainly still do that - but my boat IS rated for 200. As an engineer, I over-design the hell out of everything I design and build, but I can't vouch for any boat manufacturer, who has to balance cost against performance. That's a tricky balancing act, and more than one manufacturer has gone belly-up because their cost-cutting went too far.

Interestingly, the Mercury 60, 75, 90 and 115 are all THE SAME MOTOR, with different programming in the ECU. Arguably, you could "detune" that 200 to limit it to 150 HP, if it were a real concern (and this case it might be). I suppose that just limiting the RPMs (with that manual limiter - the throttle) would be sufficient.

roscoe · Apr 1, 2013

Re: Is It Too Much Horsepower????

smokingcrater said:
The iboats crowd is going to jump all over you, but it is not 'illegal' to overpower a boat, much like it isn't illegal to add more horsepower to your car... Also, insurance generally doesn't care what the plate in the boat says.

Well, it certainly is illegal in some states, Wisconsin being one of them.
Illegal to use an overpowered boat.
Illegal to sell an overpowered boat.
And my insurance company asked both, the rated hp capacity and the hp of the motor on the boat.

BonairII · Apr 1, 2013

Re: Is It Too Much Horsepower????

Good point about the PO NOT having to use the extra ponies.

Also depends on whether the PO's boat is going to be heavily laden with people and gear.....and the roughness of the water he boats in.

ezmobee · Apr 1, 2013

Re: Is It Too Much Horsepower????

If the max rated HP for this boat aligned with what was typically a 4 or less cylinder motor, I'd probably not run it. However, a 150 is a V6 typically so the 200 is at least the same form factor and probably nearly identical weight (I do realize HP ratings involve much more than weight). This is a pretty beefy looking boat especially with the closed bow. I'd run it. Just be careful. I'm sure it will be a blast.

Is It Too Much Horsepower????

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