12 foot motor

[ping]

I have a 12 foot fiberglass sportfisher boat from sears. It was made in 1978. I am thinking about getting an motor for this boat. I was considering purchasing a 9.9 or 15 horsepower 4 stroke honda motor to use on this boat. I read the specs of the boat and it says to only mount a 10 horsepower on it, but I was wondering becuase the 15 horespower weighes almost the same. Also is there any way to make the transom stronger on the boat even though it is only 12 feet long. I only weigh about 115 so even if i put a a bigger motor on the boat it will stay way under the maxium weight of the boat. I have read many other posts on this website and I have found it very usefull.

 

[ob]

Re: 12 foot motor

The 9.9 will push that little boat just fine.I would stay within the plackard HP rating.

 

[FlyBoyMark]

Re: 12 foot motor

The 15 HP will work out nicely for that boat. I used to have one with a 20 HP Merc(old weed angle model) on it and it had nice crisp performance with a nice plane at about 30 MPH with jus me in it and a lite load of gear. The only catch is make sure in your state its not illegal to put more than the placarded HP. In Florida you can mount a 25 HP ifya wanted.....Jus make sure the transom is still in factory shape. That little boat if it was kept out of the sun is a real tuff hull.

 

[steelespike]

Re: 12 foot motor

If you go with a 15 you are increasing the hp<br />by 50% that sounds like a lot to me.So you are overpowering the boat and adding a motor that weighs more than the original 2 cycle type 10 it was designed for. Then there are the possible legal problems,law suits etc.

 

[FlyBoyMark]

Re: 12 foot motor

Hmmmmm.....Pleasure Police at it again.... <br />We've been over this a hundred times on this BBS. The placard for the HP on the boat is a GUIDE and NOT the LAW as per the Coast Guard. The only places that it is the LAW are states that use the placard guide as the maximum rating via STATE statute. There are many states where it makes no difference. Most all of the manufactures ratings are based on weight and not what the HP is on transom. If the 15 weighs the same as the 9.9 there is little difference other than 5 MPH at best. <br />Ping...What state are you in?

 

[JB]

Re: 12 foot motor

The second most common cause of fatal accidents on the water is an overpowered boat. Overpowered meaning powered in excess of the USCG recommended SAFE maximum. The most common is another form of operator stupidity, drinking on the water.<br /><br />That skiff is rated for a 9.9, 2 stroke engine weighing 60 or so pounds. A 4 stroke 15 weighs over 100 and is 50% over SAFE power.<br /><br />You need to get real about ethics and responsibility, FBM. What you choose to do at your own risk is one thing, recommending it to someone else is another.

 

[FlyBoyMark]

Re: 12 foot motor

I love posting this link, it usually settles all arguments: web page <br /><br />HP is "unlimited" on the placard.....

 

[John Reynolds]

Re: 12 foot motor

I just had to jump in here after reading the last couple of posts. Seems to be two main issues, weight and speed. FBM did qualify his statement with “If the 15 weighs the same as the 9.9 . . .” And Ping did say that “the 15 horsepower weighs almost the same.” So I’d clear him of the “ethics and responsibility” charge on that point. That takes care of half of it. But about the other half; is the statement “. . . little difference other than 5 MPH at best” accurate? If so, is that safe? If inaccurate, about how fast and how unstable will the platform be? Is the placard for the HP on the boat the USCG recommended SAFE maximum? I don’t mind being educated on these things. <br /> I just thought that JB’s statement may have been a little too harsh. But perhaps JB’s interest is in the best interest of this forum, and is trying to protect this forum. I’m cool with that.

 

[FlyBoyMark]

Re: 12 foot motor

Here's something to consider: How fast would the boat go with a 9.9 and a 150 lb person with no other gear? How fast would the boat go with 2 guys that weigh 200 lbs apiece and a 15 HP?

 

[fish4970]

Re: 12 foot motor

what is the law in texas <br />i have a 18.5 foot runabout rated at 150 hp<br />but the motor went south (88spl)<br />picked up a great runing 78 merc 175 black max<br />for $300 <br />am i ok

 

[ob]

Re: 12 foot motor

JB is speaking from what his years on this earth have taught him to be good advice to a person posing a specific question as to the HP recommendation for a given boat hull.Fact is , JBs advice can't come into question.The only advice that can come into question are those that deviate from the design parameters of a given boat hull.<br />I had surfboards that were 12 ft long in the sixties.Put this 12 ft boat in a choppy wind driven scenario in a following sea and you will all but understand why it is not responsible to advise overpowering or overweighting a given hull.<br />What JB points out is that if I choose push design parameters ,it is not responsible advising others,particularly those who felt the need to ask the question in the first place ,to do as I do.

 

[John Reynolds]

Re: 12 foot motor

If you put me and my wife in that there 12' boat, you'd get it bogged down for sure real good. Ha ha.

 

[FlyBoyMark]

Re: 12 foot motor

30 MPH for the skinny guy and 9.9...<br />29 MPH for the two average guys and 15....<br />Using NEW 4 cycles<br />as per Mercruy charts

 

[John Reynolds]

Re: 12 foot motor

Let’s say this forum is about highway driving. The interstate speed limit here in Okie land is 75. That’s the “plackard HP rating”. But I tell Jack that 77 is just fine. But Joe tells me that I “. . . need to get real about ethics and responsibility . . .”. but I’m assuming adult behavior, wisdom, common sense, and good conditions. In fine weather, light traffic, a GOOD VEHICLE, with a skilled pilot, 80 mph may be fine. But in rotten conditions, 50 is too fast sometimes. With a lot of ice, 25 is pushing it.<br /> Only Ping and her husband are ultimately responsible for what they do, and they should take all advice and information and weigh it in light of ALL of the conditions. 9.9 hp COULD be too much . . . if you “put this 12 ft boat in a choppy wind driven scenario in a following sea . . .”.<br />There is the letter of the law, and the spirit of the law. The letter helps us develop the spirit, but the spirit is superior.

 

[FlyBoyMark]

Re: 12 foot motor

Well said John and exactly what I'm driving at

 

[JB]

Re: 12 foot motor

77 vs. 75, John??<br /><br />More like 85-90, even 100 vs. 75. And then when he kills a bunch of folks, what is your accountability??<br /><br />You are offering an excess of less than 3% as an analogy to an excess of over 50%. Not analagous.<br /><br />FlyBoyMark. Yes, you are correct, of course. <br /><br />It is not a crime to be stupid in most states, but try to explain that to a judge when you have been willfully negligent in contributing to an accident.

 

[ping]

Re: 12 foot motor

I live in New Jresey are thier any laws in this state regarding the horsepower.

 

[John Reynolds]

Re: 12 foot motor

Normally I like to use an extreme analogy (you’d have your large numbers then, JB) to get the point across, but I thought that in this occasion I would use the highway scenario since that’s familiar with everyone. Now I believe I did mention a posted speed of 75, and conditions worthy of 25, which is a disparity of 300%, is it not? <br />There is nothing wrong with the analogy; it’s just a matter of degree. The analogy is good when one considers it’s purpose and the spirit of my end of the discussion, , which is to stress personal responsibility and critical thought. But of course, matters would be more complicated, beyond mere personal responsibility and good sense, if the boat that this thread is concerned about was to be used in a commercial venture. But after all, it’s just a little boat, and a 9.9 hp is a little motor, and a 15 hp is still a little motor, and “. . . when he kills a bunch of folks . . .” (a bit strong, isn’t it?) he certainly should have “accountability”, but I really think he needs a larger boat to kill “kills a bunch of folks”. Can you get a “bunch of folks” in a 12 footer?

 

[JB]

Re: 12 foot motor

Let me tell you of the case that made me so fanatical about NOT overpowering a boat.<br /><br />The state, MA. The time, early 70s.<br /><br />My friend allowed his son to put a 40HP engine on his duck boat, rated for 20.<br /><br />The boy hit a wake, according to witnesses, at high speed and flipped the boat bow over stern. The boy was knocked out and died.<br /><br />My friend, who had just lost his son, was charged with willfull negligence and convicted.

 

[NathanY]

Re: 12 foot motor

There is not that much difference in a 9.9 and a 15. Lets get real here, a 15hp motor is not gonna make a boat rated for a 9.9 dangerous. This area is my specialty. I run these little boats 365 days a year, rain, snow, or shine. I cant believe there is still a discussion over this.<br /><br />In short a 15 is not gonna do much more for that boat than a 9.9. So every needs to chill out. It is not like he is going to put a 30hp motor on the boat.<br /><br />Some of you people really **** me of on stuff like this. If the owner of the boat wants to put a 15 on it, WHO CARES, He can do what ever he wants.