motor on pram

kayakn

Seaman Apprentice
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Feb 5, 2008
Messages
44
i am going to get an 8' pram and a 2.5 horsepower motor to go on it while i am not sailing or rowing it. i was wondering how fast it will go and if there is anything i should know about motoring it.

thanks, kayakn
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: motor on pram

boating safety, depends on the pram, and load. calm water only.
 

kayakn

Seaman Apprentice
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Feb 5, 2008
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44
Re: motor on pram

the boat is an Optimist Pram there is probably only going to be 350 pounds max load at the most. but mostly it is going to be around 200 pounds max in a small creek with not many waves.
 

bjcsc

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Jun 1, 2006
Messages
1,805
Re: motor on pram

The speed (in knots) will be the square root of the length of the water line measured from the middle of the transom, around to one side, and to the point on the bow x 1.34. Generally, you want 1hp for every 500lbs total weight to reach hull speed.

Is a pram a gaff-rigged catboat / rowboat of sorts? (never heard of one)...
 

kayakn

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Feb 5, 2008
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44
Re: motor on pram

a pram is a gaf-rigged small flat bottom boat. the one i have is an Optimist Pram that can be sailed, rowed, and i am going to try and motor it
 

bjcsc

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Re: motor on pram

Unless you plan on planing it (I wouldn't) that formula I gave you will give you your hull speed and the 2.5 should be more than adequate to get there. The only major consideration I can think of is submersion, i.e. many small sailboats roll quite easily. I've tumbled my Hobie 16 end over end quite a few times...
 

kayakn

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Feb 5, 2008
Messages
44
Re: motor on pram

this boat is what they use to train kids to sail and is said to be very safe. i will try the motor and will go very slow and see its limits, and if it does not work i can just sell the motor and sail and row it.
 

bjcsc

Lieutenant Commander
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Jun 1, 2006
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1,805
Re: motor on pram

OK, then it's probably pretty beamy. I think it will work fine...
 

steelespike

Supreme Mariner
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Apr 26, 2002
Messages
19,069
Re: motor on pram

If your running without the mast it will probably be fine.2.5 is more than enough to reach hull speed.Just be sure the transom is strong enough for an outboard.
 
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