hp rating

[Dookie]

Hey Everyone! I have a 14ft sea sprite. It says the max rated outboard i can put on it is a 60hp. i have a 85hp i was wanting to put on it. does anyone know what the pro's or con's might be if i attempt to do this.....Can i add more support to the transom? And how to add it?????? Thanks

 

[JB]

Re: hp rating

Don't do it, Dookie. <br /><br />The power rating is based on the whole boat. . .how much weight can be on the transom for safe reliable handling and how much torque it can handle safely.<br /><br />Different places take different attitudes about overpowering. In some places it will get you busted and fined, some insurance companies will not cover it. Other places don't care one way or the other unless you cause an accident. Then you are toast.<br /><br />A lot of people ignore the rating. Some of them get away with it, some of them get dragged off the bottom of a lake, some of them spend the rest of their lives paying off a damage or injury judgement.<br /><br />Swap the 85 for a good 60.

 

[ZmOz]

Re: hp rating

Here's a post I made about a month ago on a similar topic...<br /><br /> posted October 21, 2003 10:16 PM <br />--------------------------------------------------------------------------------<br />It depends on the design and condition of the boat. Usually this forum will allways say to NEVER go above the rating, but I don't agree with that at all. When the rating is made they just use a calculation based on the dimensions and weight of the boat, or something like that, I don't remember, but it doesn't really have anything to do with how well the boat handles at speed or how strong the transom is. My boat, for example, is a Glastron CV-16 rated for 120hp max. I have a 150hp on there and it's been there for 30 years. No problems what-so-ever...except the motor is dead because I forgot the oil. The majority of other owners of the same boat that I have talked to have 135 or 150hp. It only does 50mph with 150hp, and it is a SPEED boat. I can't imagine what you would do with 120hp or less, wouldn't be good for skiing, wouldn't be a speed boat, wouldn't be a fishing boat...<br /><br />Anyway...if your boat is strong and you don't go WAAAY over the rating, you should be fine, other than insurance reasons. If you're worried about that use the cowling from a smaller engine. <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=007172

 

[Dookie]

Re: hp rating

Yeh, You Have a Pretty Good Point There. I'm Gonna Take Your Advise And Look Around For A 60hp motor. Thanks!

 

[cggcpa1]

Re: hp rating

Yeah better safe than sorry..... I once always contemplated exceeding the HP ratings on my former boats... but in general the rated HP is a good measure of what you should put on there. If you do exceed the HP rating, you probally need to be a little more "gracious" in operating the boat.. not making turns at full speed, only achiveing full speed while going straight ahead, ect. Good luck...

 

[MrBill]

Re: hp rating

Pro: Your boat will go faster...<br />Con: Your life span will be shortened...

 

[Dookie]

Re: hp rating

Thats A Good One Mr Bill! I Will Absolutly Keep That One In Mind. Thanks!

 

[jd_smith]

Re: hp rating

Hey Dookie, <br /><br />Just repowered and exceeded HP by 15 (from 125 to 140), so far so good, boat is a little different handling, basically from the extra power so some compensation is needed. The boat was underpowered to begin with though (Force 125 to Johnny 140) but man what a difference! I'll keep you posted.

 

[Dookie]

Re: hp rating

jd smith..When you say different handling what do you mean? the ride? turning? does the *** end sag?<br /> Yeh, please let me know what you experience. What Is The Lenth of your boat? Thanks

 

[jd_smith]

Re: hp rating

Dookie, <br /><br />I have an 88 Bayliner Bowrider that is 19.5' long and weighs about 2800lbs dry. I love the boat for its durability and flexibility (fishing/sking/cruising.) I just got the boat back last week and have had it out twice so more to come. Took her out on Long Island Sound for some fishing and noticed a couple of things. The boat doesn't sit any different but the increase in bowrise when accerlating is substantial, not dangerous in calm water but probably could be in some chop. The bowrise quickly fixes itself so I accelerate a little slower. I think some trim tabs might help so I will be installing those next year. Cornering is about the same, but I throttled down to avoid any problems until I really get a feel for the boat. Handling at slow speeds is also a bit different, the new motor has a lot more torque and the boat almost jumps around, but I suppose that could be something I get used to over time. The boat is also affected far more by the actual position of the motor (trim/tilt), I am still trying to figure out exactly where it needs to be at higher speeds. I am keeping an eye on the transom but I forsee no problems there either as the weight difference in motors is not much. For me the swap was a complete success, boat now pushes well over 50 mph when she used to struggle to get to 40, acceleration is faster and I expect gas consumption to actually decrease because I plane off with less throttle. I feel like I have a new boat and fell in love with her all over again. Can't wait for the spring!

 

[mellowyellow]

Re: hp rating

if you have an accident, you will be held personally liable because you exceed the max. hp.<br />insurance will use this as a reason not to pay and you will be up the creek without a paddle.<br />don't do it!

 

[OBJ]

Re: hp rating

Guys...I can't re-emphasize JB's and mellowyellows posts'....You overpower and yer' flirting with trouble. Even 15hp....or as little as 5. Boats, any boat, is rated for a particular hp for a reason. Don't put yourselves in harms way cause it's cool.<br /><br />We enjoy everyone on the forums....want ta' keep everyone safe.

 

[jd_smith]

Re: hp rating

Just to clarify, I only know what worked for me and my boat, in my case it worked. I have had it for 5 years and pretty much knew what I was getting into. Insurance and other problems could exist. In no way do I want to promote anything that could be dangerous! I changed my motor because my Force left me stranded out in the ocean and I had a $2000 tow bill then over the summer put over $1400 in new parts into it only to have the trim/tilt go, I refused to fix anything more on a poorly built weak 125HP Force. The Johnson was a good motor at a solid price, and for my boat I felt it would be fine. Didn't swap for more power, but for dependability and peace of mind!<br />Thanks all!

 

[LubeDude]

Re: hp rating

JD_SMITH:<br /><br />A boat that size was probably rated to at least the 140 you put on it, Id guess 150! I cant beleive it was rated 125HP!<br /><br />LubeDude

 

[mellowyellow]

Re: hp rating

"88 Bayliner Bowrider that is 19.5' long and weighs about 2800lbs dry"<br />125hp seems low for this set-up, but why would<br />it receive this exact coast guard rating? <br />no reason? hmmmmm....<br />JD buddy, it's a negligence lawsuit waiting to<br />happen IMO. and there's no good reason to put yurself<br />in this spot...

 

[jd_smith]

Re: hp rating

Believe it or not, that was the hp rating, 125. Thank you for the input MY, I will keep it in mind when operating, but I stick by my decision.

 

[usedboats4u]

Re: hp rating

here is the real skinny from a boat builder, the united states coast guard gives us a formula based on length, width, height of tramsom and remote or tiller steering, that is used to determine max hp, as a boat builder we can rate a boat at that max hp OR anything below that we wish. that is why you get bigger boats like bayliners with small hp ratings, i do not recommend overpowering boats and will not do it for my customers, this is all based on insurance claims, if you decide to overpower check local laws and with your insurance company first.

 

[vidar]

Re: hp rating

Hi! once we had a 13 feet hurricane w a 90 johns on it..... darn stupid YES... had to run it aground when we slowed down or we swamped it..... but man it flied.....but we replaced it w a40hp and it worked a lot better....take care and be safe.. Dont overdo it..

 

[cobra 3.0]

Re: hp rating

Here's a twist! I have a 13 1/2 foot Princecraft Cartopper rated for 25 hp that I use for fishing. This is a 135 lb boat with a slight v in front and has more of a flat bottom. We had an 18 hp Merc on it an I honestly felt it was very close to being overpowered. We now have a 15 hp Erude and it is plenty fast (will hit over 30 mph with one guy and 25 mph with 3 people) and much safer due to less engine weight giving it easier handling. In my opinion 25 hp is not a safe rating on this boat.<br /><br />So you have to question ratings and their validity. The above boat is about 25+ years old. I doubt that today it would get this rating. Law suits are more common than burgers and fries. Manufacturers lean towards being extra safe and probably keep hp rating low to avoid getting sued.

 

[Lark40]

Re: hp rating

Cobra 3.0,<br /><br />Have you verified those speeds with a GPS?<br /><br />I have an antique aluminum runabout, which has a semi-racing hull and weighs 250 lbs. <br /><br />With either the 1960 Evinrude Lark 40, or the new Johnson 30, I have to strip everything out of the boat and use a 15" prop to barely hit 30 mph measured by GPS. Your speeds seem wildly high.<br /><br />(In case you're wondering.... I weigh 160.)