Over Powered?

[wilkin250r]

What is involved in the max horsepower rating of a boat? What happens if I exceed that? I can't believe it's just an issue of the weight ofthe outboard.

 

[Kenny Bush]

Re: Over Powered?

Wilkin, there is more to the rating than the weight of the motor. I do not know what the rules are for your state, but in texas the law can(usually don't)write us a ticket. Now I have on several occasions exceeded max HP. I have built several go fast boats and on a couple, I almost tripled the HP(I feel the need for speed)rating on the hull. I do take note of the transom as well as the floatation before increasing hull rating. Most hull ratings I see take passengers(and weight)into account for the spec. When I increased HP, I dont take passengers or extra weight. I usually reduce these to compensate for larger/faster motor. Goodluck......BushCat

 

[wilkin250r]

Re: Over Powered?

Thanks, bushcat, you sound pretty knowledgable. Tell me, do you know why boats have a horsepower rating? If it WAS just weight issue, if figure it would have a weight rating.<br /><br />My problem is, I'm a novice at this, and I bought a fixer-upper boat, and then I bought a 200hp engine. Turns out my boat is only rated for 125 hp. I REALLY don't want to re-sell this engine.

 

[wilkin250r]

Re: Over Powered?

http://www.boats.com/content/default_detail.jsp?contentid=2902

 

[wilkin250r]

Re: Over Powered?

This is great, I'm finding all kinds of stuff.<br /><br /> http://www.abycinc.org/Resources/ABYC News/how_much_power_is_too_much.htm

 

[wilkin250r]

Re: Over Powered?

Does anybody have any advise?<br /><br />I'm wondering why a 16ft Bayliner can have a 220hp I/O, but the same size boat with an outboard is only rated for 125hp.

 

[Franki]

Re: Over Powered?

For one thing.. a 220 outboard would leave a 220 IO for dead..<br /><br />Secondly, there is alot more weight, and its alot lower in an IO. (more stability.)<br /><br />Thirdly, the IO's weight is not hanging off the back of the tramsom..<br /><br />Any or all of those factors would be a good reason to limit the HP..<br /><br />If you have an older bayliner, who knows what condition the wood in the transom is.. <br /><br />you might put the huge OB on there, and lose it and half the transom the first time you go out...<br /><br />if its not designed for the weight.. then you might regret making the decision..<br /><br />get the 200 if its a bargain, and then swap it for a newer motor of the correct HP...<br /><br />its safer..<br /><br />rgds<br /><br />Franki

 

[wilkin250r]

Re: Over Powered?

Would there be any problems if I wanted to go with a 115hp four-stroke? I don't see a problem with that. Would anybody argue that it will sink the back of the boat? Why would it, it's within the correct HP rating ofthe boat.<br /><br />The 115hp four stroke wieghs about 10lbs more than the 200hp two-stroke.<br /><br />I'm not trying to start a fight or an arguement, I just want to look at all sides of the issue and get as much information as I can. It would be pretty stupid of me to proceed blindly without gathering information first.

 

[wilkin250r]

Re: Over Powered?

By the way, I agree that the weight distribution in an I/O is much more stable than in an outboard situation.

 

[rickdb1boat]

Re: Over Powered?

Just an example:<br />A johnson 115 2 stroke weighs 319#. A Yamaha 115 4 stroke comes in at 405#. That's a pretty big difference. Not saying that your boat couldn't handle it, but I would sure check out the transom to be sure it's solid.

 

[wilkin250r]

Re: Over Powered?

Ok, so let's assume for a sec that the transom is solid in good condition. This I will DEFINITELY verify.<br /><br />What else should I look into before I think about putting a 200hp engine on?<br /><br />The reason I'm so he11 bent on trying to get this 200hp engine is for water skiing. I had a 110hp engine on an old boat and it could not drag me out of the water on a single ski, and I was 60lbs lighter then. I don't think a 125 will do it, especially if I want to wakeboard, which will require even MORE power to get me up.<br /><br />The obvious reply would be "spend the money on a better boat"<br /><br />I don't have that much money. <br /><br />I bought this boat because the engine was dead, so it was cheap, and I had a line on a good engine. Now that my little dream is so much closer to reality, I can't go back!!

 

[ob]

Re: Over Powered?

wilkin250r,I will not attempt to convince you not to bolt the 200 on your boat but rather explain that the HP ratings are established not solely on weight but rather on the hull design and ergonomic handling capabilities of the hull.Simply put,you will be at a loss of control risk under certain water conditions if you are not a seasoned high HP to weight ratio savy boater.

 

[wilkin250r]

Re: Over Powered?

I realize that the rating is not based solely on weight. As far as I can tell, it is based on the ability of a boat to execute a hard turn, at full throttle, with the max rated HP without loss of control or ejecting the driver.<br /><br />This, to me, seems absurd. There are very few cars that can execute a hard turn at full speed without loss of control, yet they are not required to have a horsepower rating.<br /><br />I honestly do not WANT to go full speed with a 200hp engine. That's kinda scary to me, and if I DO put this engine on this boat, it will be many months before I even attempt full speed. I just want the extra HP to pull me out of the water, quickly. <br /><br />I can't imagine anything more aggrevating than owning your own boat that doesn't suit your needs.

 

[ob]

Re: Over Powered?

Wilkin250r,I don't get it.You post a question admitting to be a novice at the hobby of boating,yet when given sound advice in your best interest you question the outcome.What is absurd is comparing the handling characteristics of an automobile to that of a boat.Consider yourself advised.I'm finished.

 

[ob1jeeper]

Re: Over Powered?

wilkin...<br />I believe what ob is trying to say is that you are playing with a fire you don't yet understand...<br /><br />IE, just as your hull is not designed for this much HP, riding lawn mowers aren't designed to be operated with 200 hp motors @ 60 mph, either...<br /><br />YES... You COULD operate EITHER the boating combination you've described, OR the afore-mentioned "fictional lawn mower" safely ... If and this is a REALLY BIG IF !!!, You are seasoned in the mechanics of boating, and have the sense and knowledge to keep it "under TOTAL control" at all times...<br /><br />The problem I see, is that you are putting a HUGE motor on a boat, supposedly so that YOU can ski behind it... This begs the question of what level of experience will your driver have with this combination,while towing you ??<br /><br />If, as you say, you are an admitted novice, I'd be willing to bet that most any driver you might have along will typically have no better experience level than yourself... which could be a FATAL combination.<br /><br />Like ob says... Why ask for advice, if you don't want any that doesn't agree with what you want to hear, or doesn't tell you that all is "Just Ducky" with this flawed line of thinking ??<br /><br />If it were MY family that was going to be on the boat, it would be powered by a motor, of proper HP ratings for the hull... But then that's just me... My choice would be to put thier safety, that of fellow boaters, and my own safety above my "need for speed"...<br /><br />Good Luck, Obiwan Jeeper

 

[JasonB]

Re: Over Powered?

I would trade that 200 for a motor that fits the HP rating of the boat. I have a 16' tri-hull with an 85hp Johnson. I have pulled upa 230lb skier on 2 narrow skies and a 170lb slalom skier, I also had 4 adults in the boat. I would also be leery of that 115 4 stroke as it will likely be too heavy and throw off the handling of the boat by making it stern heavy. If your rating is 125, go find a 115-120 Johnson or Evinrude V4. My 85 has load of low end geddyup. I believe you will have no problems skiing with a 115-120. Just make sure the boat is solid before you hang ANY motor on it. If the motor you had before was a Chyrsler/Force, it may not have had the HP it claimed. A Merc 115 would also be a good choice, but I think the OMC's have a bit more low end where the Merc has a bit more top end. Whatever you get, carry two props. With my 85, I carry a 15 pitch for skiing/tubing and a 17 pitch for cruising. I can get a skier up with the 17 and some patience, but the 15 puls them right up. I bet that 110 would have done the job if it had a lower pitch prop.

 

[JasonB]

Re: Over Powered?

By the way, there is no way I would hang a 200 on a boat rated for a 125. No way, no how. It's not worth it. If you really want the 200, geta boat that is rated for it.

 

[snapperbait]

Re: Over Powered?

If you plan on Insuring your boat (which I highly recomend especially since your watersking, because injurys do happen), I don't think theres an insurance company that would insure you with the 200 on a boat thats rated for a 125...

 

[G DANE]

Re: Over Powered?

Hi wilkin 250r, i´d like to pop in here.<br /><br />Two young guys lost their lives three years ago at the bay here, they put a 115 hp Yamaha on a boat that was rated for 50 hp. Going in 3´wawes, the boat develeoped a 3´crack at the chine midtships and sunk imediately. They did not wear lifewests, and probably swam as long as they could.( boat was later found ) They both died, 21 and 23 years old - very sad. The biggest safety factor of coarse is the drivers sence and feeling of what the boat can handle. BUT I told you this to explain that hp rating is not only a question of transom strength, but the intire hull, and design too.

 

[G DANE]

Re: Over Powered?

Another thing.<br /><br />The hp ratings are all calculated based on 2 stroke weight factor, on oldeer boats. I think we will se ratings including motor weight sometime. Depending of type of boat of carse, you should have no problems skiing behind a 125 hp, I have been doing a lot of sking behind 50 and 60 hp, its a question of technique too, but with one ski and a 50 hp the boat will loose speed when you cross the wake.