i have a 14 ft. flat bottom with a 15 hp and i get about 16 mph out of it with two guys and a dog. so you should have enough motor. your motor could be angled wrong, if the boat is flat the motor should be at a right angle to the hull. if it is anlged up too much you will never get on plane.or most boats, 15 mph +/- or so is enough for it to run on plane. It's important that you run the boat with just you in it. My 14x48 ran so fast with just me in it that it would chine walk a little bit. I never GPS'd it, but it was fast.
http://www.ducks.org/news-media/messageboards/PrintTopic691034.aspx
As for the used boat you found, a 5.5 on a 14 foot v-hull seems a little weak. It will probably have a hard time getting on plane with a couple of fellas and gear loaded into it. My 12 foot flat bottom jon with a 5 horse will plane with me and one of my dogs (~320 lbs) but not with both dogs (~420 lbs) on board.he V hull is usually deeper, with more legroom. I had a 12' flat jon w\4 hp and due to it's low profile, got uncomfortable fast. On a 14' alum boat I would look for 10-15 hp min. if you want to plane.
http://www.thehulltruth.com/boating-forum/39325-jon-boats-v-hull-versus-flat-bottom.html
Take your boat weight and divide by 50. So, a 1000 lb boat (boat, motor, gear, passengers), flat bottom or still water would take 20HP to plane. If your boat with all gear is heavier, it will take more HP to plane.If your boat has a v-hull, it will take more HP to plane.If your boat is in rough water, it will take more HP to plane.Note: this is only to plane, not run around at 30 MPH. So, let's look at this. You have an aluminum boat that weighs 450 lbs. You weigh 250 lbs. You carry 6 gal of gas (total weight approx 48 lbs).This is now a total of 750 lbs. You will need a MINIMUM of 15 hp to plane. So, you stick a 15 hp engine on it and you are happy.ou have an aluminum boat that weighs 450 lbs. You weigh 250 lbs. You carry 6 gal of gas (total weight approx 48 lbs). This is now a total of 750 lbs. You will need a MINIMUM of 15 hp to plane. So, you stick a 15 hp engine on it and you are happy.
http://forums.iboats.com/forum/general-boating-outdoors-activities/boat-topics-and-questions-not-engine-topics/246601-boat-weight-to-hp-ratio
A flat bottom carries bubbles straight back. The boat on the inside page of the brochure is an aluminum flat bottom with a 48 inch (4 ft.) bottom (45HP) and 14 ft. overall. This design works well, but will ingest some air when running with the wind in a chop.This can be helped by the use of intake fin side skirts. flat bottom carries bubbles straight back. The boat on the inside page of the brochure is an aluminum flat bottom with a 48 inch (4 ft.) bottom (45HP) and 14 ft. overall. This design works well, but will ingest some air when running with the wind in a chop.
http://outboardjets.com/boat-selection/
If you fish with 3 or more people and wish to get up on plane you should go with no less than a 20 hp outboard. Performance. You can expect to go about 20-30mph on most light boats If a 9.9hp-18hp barely planes your boat a 20-35hp will be a sufficient upgrade.f you fish with 3 or more people and wish to get up on plane you should go with no less than a 20 hp outboard. Performance. You can expect to go about 20-30mph on most light boats If a 9.9hp-18hp barely planes your boat a 20-35hp will be a sufficient upgrade.
http://smalloutboards.com/choose.htm
HP =. (0.8 x Factor) -25. So if your 14 foot boat is actually 13.83 (13 ft 10in) and has a 4.5 ft transom width the factor will be 62.23. If it has a 20 inch transom height and remote steering then 62.23 X 2 -90 = hp = 34.47 round that to 35.o if your 14 foot boat is actually 13.83 (13 ft 10in) and has a 4.5 ft transom width the factor will be 62.23. If it has a 20 inch transom height and remote steering then 62.23 X 2 -90 = hp = 34.47 round that to 35.
http://www.answers.com/Q/What_horsepower_do_you_need_for_a_14_foot_boat
Let's add say 100 pounds for a minimum motor and maybe 50 pounds of fuel and 50 pounds of general gear and maybe 200 pounds for you and you are floating 1000 pounds. That would be about the minimum weight the boat would ever be used at. Apply the old rule and you will need 20 hp to have a chance to plane it.et's add say 100 pounds for a minimum motor and maybe 50 pounds of fuel and 50 pounds of general gear and maybe 200 pounds for you and you are floating 1000 pounds. That would be about the minimum weight the boat would ever be used at. Apply the old rule and you will need 20 hp to have a chance to plane it.
http://www.duckworksbbs.com/plans/jim/jon20/index.htm
Re: Minimum Horsepower Boats (Flat Bottom). The most efficient motor flat bottom boat i have ever heard of would have to be a proper power sharpie like Russel R by John and William Atkin. It is a true semi displacement hull, with a wide transom and some, but not extreme, aft rocker.e: Minimum Horsepower Boats (Flat Bottom). John Gardner recorded the lines of a 28' Chasion power dory that did 9mph with a 6 hp through any type of weather. At the time it was built 9mph was a real speed boat.
http://forum.woodenboat.com/showthread.php?133062-Minimum-Horsepower-Boats-(Flat-Bottom)
Re: Minimum Horsepower Boats (Flat Bottom). It is a supreme 2048, a gussied up version of the Shawnee river boat. It is narrow by modern standards but not quite as narrow as it looks and a whole lot wider and more useful than the sneakeasy, 48 wide bottom, beam over 5 feet at the gunnels for the whole length.e: Minimum Horsepower Boats (Flat Bottom). John Gardner recorded the lines of a 28' Chasion power dory that did 9mph with a 6 hp through any type of weather. At the time it was built 9mph was a real speed boat.
http://forum.woodenboat.com/showthread.php?133062-Minimum-Horsepower-Boats-(Flat-Bottom)
I would suggest that on a typical 14' jon 15 HP would be the most you would need. I have made good planing speed with a 5 horse engine in a 12 foot flat bottomed coleman crawdad with 2 adults in it along with a couple of coolers and fishing equipment. 25 hp on a 14 ft jon boat? Would it be dangerous to put a 25 horsepower on a 14 ft. flat bottom jon boat?
https://answers.yahoo.com/question/index?qid=20091206165407AAFuvU0
how many horsepower needed to plane a flat bottom boat
There are 20 horsepowers needed to plane a flat bottom boat. 20 horsepower is needed to plane a flat bottom boat.