12 ft aluminiun boat Hp rating

[yzchamp]

Label on my 12 ft aluminum boat says that max horsepower rating is 12 HP .What will happened if i put 20 HP on it? beside going fast of course.. i got 8hp honda that wont plane this boat with 2 ppl and gear , buddy gave me his old 20 hp merc, .....

 

[Bondo]

Re: 12 ft aluminiun boat Hp rating

Label on my 12 ft aluminum boat says that max horsepower rating is 12 HP .What will happened if i put 20 HP on it? beside going fast of course.. i got 8hp honda that wont plane this boat with 2 ppl and gear , buddy gave me his old 20 hp merc, .....

Ayuh,... There's a pretty good chance you'll eventually go Swimmin'...

Or Drown...

 

[joekacker]

Re: 12 ft aluminiun boat Hp rating

yeah, too much stress on the transom, Not to mention the coast guard, getting on your butt

 

[wifisher]

Re: 12 ft aluminiun boat Hp rating

12 to 20 is a pretty big jump. The rating on the transom is decided by the stress that the motor will exert on it from the thrust. A 20hp is a little less than twice what your boat is designed for. The first thing that you should be concerned with is the transom getting ripped off of the boat. The motor and transom will be on the bottom of the lake, and the boat may stay on top if there is foam in it.

That is more motor than I would even consider on a boat that size.

2 ppl and gear in a 12ft probably puts you at or near the weight capacity of the boat. If you want to go faster, get a bigger boat.

 

[roscoe]

Re: 12 ft aluminiun boat Hp rating

Many 12' boats will not plane as one would expect.
I have a very heavy-duty Meyers 12' v-hull rated for 12 hp.
Have used a 2.2 hp, 4 hp, 6 hp, 7.5 hp, and a 9.9 hp.
The only thing that the 3 larger motors did, was make the boat handle poorly and point the bow to the sky.

 

[hungupthespikes]

Re: 12 ft aluminiun boat Hp rating

If the 20hp checks out OK them sell the 12 ft with the 8hp. Summer break is almost here and the 12ft will sell fast (good first boat, will keep the younger boaters out of mom's hair). Should give you money to get a little bigger boat that can handle the 20hp, 2 ppl. and gear.
yea 2ft itis.

 

[Hogger]

Re: 12 ft aluminiun boat Hp rating

I had a 12' Smoker Craft with a 5 hp on it. It sucked. We could hardly get up river to one of our hunting spots.
So I found a guy that traded me the 5hp for an older 20hp. What a difference! Check the rating tag on the boat, but I wouldn't go with anything less than a 15hp, especially if your carrying a couple people and gear.

 

[eterry]

Re: 12 ft aluminiun boat Hp rating

My first boat was a 14' alluminum that someone had used too much motor on. My best friend and I were at the lake running trot lines one day when the weld along the deck and transom gave way...water poured in as my friend paddled like his life depended on it (cause it did) and I bailed like hell!!! We made it to shore half submerged..wont ever do that again!

Get a bigger boat, or get used to a small boat. My .02
Eterry

 

[3gsdad]

Re: 12 ft aluminiun boat Hp rating

I think something may be wrong that you are missing. I have a 12' john boat with a 1984 9.8HP Merc. The first time I took it out it would not get the boat on plane and I was so disapointed. All of the sudden out of nowhere the motor just started running twice as fast and then slowed back down after 30 seconds. After much research I found out that one of the coils was bad and it was only running on one cylinder. I replaced the coil and it runs great! I have not checked the speed with a GPS but compared to my stingray it feels like we are going about 15 to 20 MPH with 2 adults ans 2 small kids.
Have you made sure it is firing on both cyliders?
Also have you tried to adjust the trim of the motor?

 

[yzchamp]

Re: 12 ft aluminiun boat Hp rating

thanks for the replies . 8hp runs good and planes great with just me in it, however with 2 ppl it will do 20km/h and plowes through it. i bought a 7 pitch prop hoping that it will help and compensate for extra weight( original was 8 5/8) but it did nothing beside lowering my trolling speed by 0.5 km/h.
was exited about that 20 hp merc but it sounds like it has bad idea writen all over the place...

 

[RIDEPATE]

Re: 12 ft aluminiun boat Hp rating

There is no replacement for displacement..........Put the 20 on it.........I once had a 20 on a 10-ft jon. It was a hoot, and nobody died............

 

[wifisher]

Re: 12 ft aluminiun boat Hp rating

There is no replacement for displacement..........Put the 20 on it.........I once had a 20 on a 10-ft jon. It was a hoot, and nobody died............

Lucky beats smart 100 times out of 100.

 

[BobList]

Re: 12 ft aluminiun boat Hp rating

so beef up the transom with 3/4" plywood, put a few more screws in the braces... have fun.. after all, just because you have a 20hp on a lil ole tinny doesn't mean you HAVE to use full throttle.. right?.. I mean that would be unsafe.. only go half throttle. That's the same as putting a 10 hp on her.


(yea, right...)

 

[DJ]

Re: 12 ft aluminiun boat Hp rating

Overpowering a boat is BAD advice. No matter how you look at it.

12' V's are not known for their weight carrying capacity or performance. The extra two feet in a 14' will make a lot of difference.

 

[yzchamp]

Re: 12 ft aluminiun boat Hp rating

so beef up the transom with 3/4" plywood, put a few more screws in the braces... have fun.. after all, just because you have a 20hp on a lil ole tinny doesn't mean you HAVE to use full throttle.. right?.. I mean that would be unsafe.. only go half throttle. That's the same as putting a 10 hp on her.


(yea, right...)

now we talking.. i like the idea of beefing up the transom also.. ! go fast go home, half throttle is for pussies! lol

 

[fishndirk]

Re: 12 ft aluminiun boat Hp rating

The type of boat makes a difference, flat or v bottom or mod v. Ive got a Valco U12 which had a 7.5 2 stroke, replaced it with a 20hp 4 stroke and the difference is night and day! Gets on plane right away and goes more than twice as fast. A 12ft flat bottom will probably not handle a 20hp 4 stroke cause of the extra weight and low sides but a V bottom always runs a deeper draft and can afford the extra weight. Your beam (boat width at back) is also a factor, mine is 65 inches. If its a flat bottom go with a slightly more hp engine, if its a v bottom go with the 20 and kick some a**. By the way, most new motors 15-20hp the only difference is in the carb, weight and everything else is the same. So if you like the 15 you might as well go with the 20.

 

[rallyart]

Re: 12 ft aluminiun boat Hp rating

Keep the 8 hp and get an 11' inflatable. It will carry more, weigh less, be safer, and plane easily with a couple people in it. (just sayin' if you're goin' to trade something). A good one would be rated for that 20 also.

 

[fishndirk]

Re: 12 ft aluminiun boat Hp rating

True, a 12ft inflate with a 20hp would do real good. Unless of course your running rivers and the first log or snag you hit rips a 6inch hole in your boat.

 

[joekacker]

Re: 12 ft aluminiun boat Hp rating

get a boston whaler

 

[fishndirk]

Re: 12 ft aluminiun boat Hp rating

Alumminum is much cheaper to repair than fiber glass, and can take a lot more cr*p, and alum boats themselves are cheaper. If all you ever go in is wide open sea water than who cares but if you want to transition than go with light aluminum boat with its max hp rating.