Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 20 of 20
  1. #1
    Cadet
    Join Date
    Nov 2002
    Posts
    20

    Default 12 ft aluminum boat max hp

    I have an aluminum boat with a 17" transon, 18" deep, 56" beam, 11'6" long. What would be the upper limit for hp in a boat this size?

  2. #2
    Petty Officer 1st Class
    Join Date
    Aug 2002
    Location
    Warren, Indiana USA
    Posts
    371

    Default Re: 12 ft aluminum boat max hp

    I have a 12 ft. v-bottom and my tag on the hull says 7 1/2 h.p. max. Hope this helps.

  3. #3
    Petty Officer 1st Class
    Join Date
    May 2002
    Location
    Skaneateles New York
    Posts
    344

    Default Re: 12 ft aluminum boat max hp

    I'd stay with 6-8 HP...the larger motors start to get a little heavy. You'ld be OK with a 4-5 also.

  4. #4
    Lieutenant
    Join Date
    Nov 2002
    Location
    Massachusetts
    Posts
    1,422

    Default Re: 12 ft aluminum boat max hp

    I have an 8hp short shaft for sale that would work good with that boat. You could keep that in mind.11

  5. #5
    Moderator JB's Avatar
    Join Date
    Mar 2001
    Location
    The Hideout, Whitt, TX, USA
    Posts
    45,903

    Default Re: 12 ft aluminum boat max hp

    Ahoy, KDC.I agree. I never saw a 12' "tinny" rated for even 10hp.Good luck.

  6. #6
    Lieutenant Commander Tacklewasher's Avatar
    Join Date
    Sep 2002
    Location
    Kelowna, BC, Canada
    Posts
    1,588

    Default Re: 12 ft aluminum boat max hp

    My dad has one. Rated for 15hp. When he stops fishing, I've laid claim to it as it is a nice, wide, heavy 12 footer that is much more stable than mine. Just a bit heavier so I might have to steal his boat loader as well.Mine's rated for 10 and I have a 9.9 Johnson on it. Usually just use the 30lb MinnKota though.
    1977 Starcraft 18' SS 1980 Evin 115

  7. #7
    Lieutenant Junior Grade
    Join Date
    May 2002
    Location
    Beverly, Ma
    Posts
    1,070

    Default Re: 12 ft aluminum boat max hp

    For Ryan T.How much for the 8 horse?email: mtowey@analogic.comLuna SeaBeverly, Mass

  8. #8
    Lieutenant
    Join Date
    Nov 2002
    Location
    Massachusetts
    Posts
    1,422

    Default Re: 12 ft aluminum boat max hp

    I sent you an email.11

  9. #9
    Lieutenant Commander
    Join Date
    Aug 2002
    Location
    Point Clear, AL
    Posts
    1,662

    Default Re: 12 ft aluminum boat max hp

    The answers are right about keeping the horsepower down. I stuck a 25HP Evinrude on my 12' aluminum boat one time just for the heck of it and I don't think there was anything in the water but the propellor. Extremely squirrely handling and scary. Came back slowly and carefully.

  10. #10
    Petty Officer 2nd Class
    Join Date
    Aug 2001
    Location
    Bryans Road, Md, U.S.
    Posts
    116

    Default Re: 12 ft aluminum boat max hp

    Depends on boat manufacture. 12' Sea Nymph with 20 hp Suzuki...She'll scream but she's definitely not for everyone. I scared the bageezers out of a friend of mine in it. I have a good friend with a 12' John boat with a 130 hp Allison R/R. Got a really big prop that sits about 4 feet above the water.

  11. #11
    Petty Officer 2nd Class
    Join Date
    Jul 2002
    Location
    Arkansas, Maddox Bay
    Posts
    190

    Default Re: 12 ft aluminum boat max hp

    There is a game warden here that has a 12’ war eagle with 25hp mercury. It handles well and rides good. I thought it would be overpowered but it was not.

  12. #12
    Cadet
    Join Date
    Nov 2002
    Location
    Vero Beach FL
    Posts
    27

    Default Re: 12 ft aluminum boat max hp

    I have a Sea Nymph 14R, max rated for a 25hp.I am not a "speed deamon" but would like to get up on a plane.(I am running a 4hp Yamaha).I am seriously lookig at a Tohatsu/Nissan but the 25hp is a three cylinder and is quite a lot of motor for a 14' aluminum. Would the 18hp move get the boat up?

  13. #13
    Seaman
    Join Date
    Dec 2002
    Location
    Peachtree City, GA
    Posts
    68

    Default Re: 12 ft aluminum boat max hp

    I've got an old Merc 60 (6hp). It does alright on my 14ft jon boat. Mine is about 4ft wide and about 3ft wide at the bottom. It actually rides better with two people in the boat. The extra weight up front evens the weight out and the boats rides flatter and faster. With just me in the boat (140lb), the boat will do 15mph on a glass surface. Rough water slows it to 12mph. I feel that a 9.9 is what I really should have but the 6 does the job.

  14. #14
    Lieutenant
    Join Date
    Nov 2002
    Location
    Massachusetts
    Posts
    1,422

    Default Re: 12 ft aluminum boat max hp

    Big Al,If your gas line is not to short you should try puting the gas tank tord the bow. I do it with my 11' whaler with a 15hp merc and it will plane faster and get a little more top end. When there is only one person in the boat.11

  15. #15
    Seaman
    Join Date
    Dec 2002
    Location
    Peachtree City, GA
    Posts
    68

    Default Re: 12 ft aluminum boat max hp

    Ryan, Well I have a one gallon tank that I converted into a outboard gas tank. I just drilled a hole into the cap and hot glued the nozzle in place. One gallon is not much weight. I keep a two gallon on reserve in the very front though. You did make me realize that I should move my trolling motor battery to the front on the boat. But I'll still need the terminal posts at the back for the trolling motor. I guess I could run some heavy gauge wire to the back and screw on some posts.

  16. #16
    Lieutenant
    Join Date
    Nov 2002
    Location
    Massachusetts
    Posts
    1,422

    Default Re: 12 ft aluminum boat max hp

    My boat is remote stearing and I have neaver done this before but I have seen tiller extensions when you can make them real long and sit on the bow yourself. That might help.11

  17. #17
    Lieutenant Commander CalicoKid's Avatar
    Join Date
    May 2002
    Location
    Lake Wisconsin
    Posts
    1,595

    Default Re: 12 ft aluminum boat max hp

    Here is a pamphlet in PDF form by th US Coast Guard reguarding Safety Standards for Backyard Boat Builders which contains a wealth of information and tests for building/modifying boats and will surely help you answer your question. I used these guidilines to help me make the same determination about a little boat I have without a C.G. plate. By the way the C.G. plate is not federal law, but may be enforced locally! Read this USCG page first topic. I hope this helps, I got this info from another great member of this board!

  18. #18
    Commander
    Join Date
    Mar 2002
    Location
    Fort Worth Texas
    Posts
    2,377

    Default Re: 12 ft aluminum boat max hp

    I have a 14 ft Richline ( very old boat 1965 model) and I put a 20hp Merc on it. I had a 15 on it and did not get the front up out of the water enough, got to wet all the time. Does not do that anymore though! It will run about 30 now which is entirely too fast! Only run about half throttle. All I can tell you is BE CAREFUL. I dont care what anyone says, overpowering a little boat by 5 hp is far more dangerous that overpowering a bass boat by 20 hp. I would not go bigger than a 9.9, although most popular makes ust the same engine for the 15.

  19. #19
    Petty Officer 1st Class
    Join Date
    Nov 2002
    Location
    West Kentucky
    Posts
    336

    Default Re: 12 ft aluminum boat max hp

    I have the same boat with a 9.9 Johnson & my kids have a ball with it. I would not want any more motor as long as they are running it Of course, 16 yr old boys only have one speed eh?

  20. #20
    Ensign
    Join Date
    Apr 2002
    Location
    Fort Lauderdale, Florida
    Posts
    934

    Default Re: 12 ft aluminum boat max hp

    My son has a 12' SeaNymph with one of the newer Force 15 hp on it...does 25 MPH with my 225 lb butt and his 110 lb butt, battery trolling motor and gear. Me alone....30-32 MPH...Force 15 is rated one of the fastest 15's around.....The performance is "comfortable" with a 15, I immagine it would be very sluggish with a 10 hp. Load has a great deal to do with performance and the construction of the transom with how much power it can take (i.e. 14 foot version of same hull that is identicle except for more length IS rated for a 15 HP)......tread carefully.....adjust the HP to your specific needs within reason.

Similar Threads

  1. aluminum floor in aluminum boat
    By Kansas Jayhawker in forum Boat Restoration, Building, and Hull Repair
    Replies: 4
    Last Post: February 14th, 2010, 08:44 AM
  2. repairing wooden transom on aluminum boat with fabricated aluminum
    By sean armour in forum Boat Restoration, Building, and Hull Repair
    Replies: 4
    Last Post: August 24th, 2009, 02:22 PM
  3. 1992 Aluminum Boat needs a good cleaning of the Aluminum Hull What works best??
    By sigarmsp226 in forum Boat Topics and Questions (not engine topics)
    Replies: 10
    Last Post: December 15th, 2007, 06:35 AM
  4. aluminum boat... aluminum stringers?
    By diaboy5681 in forum Boat Restoration, Building, and Hull Repair
    Replies: 6
    Last Post: October 17th, 2006, 08:17 AM
  5. Refinishing aluminum boat for camo duck boat
    By noluck127 in forum Boat Topics and Questions (not engine topics)
    Replies: 0
    Last Post: January 8th, 2006, 05:31 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic