retro-fit fuel pump 1956 SeaHorse 15 h.p.

RandyJ

RandyJ

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I was told two ways to convert a twin line engine to a single line fuel hose. One is to use an electric fuel pump. A few weeks ago a guy told me I could hook up a 3 line fuel pump (in,out,pulse lines). Anyone have any experience with this conversion? I tried it today using a very old fuel pump off of a 100 hp I had laying around and it did not work (not very sure I did everything correctly or if the pump was good). Any suggestions?
 
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Paul Moir

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

Have a look in Other Outboards at a post about a 12hp Gale. Very much the same engine as yours.<br /><br />I don't like the idea of the electric pump, not only because of the saftey issue but because you then have use (and rely on) a battery.
 
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jim_in_day

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

That's actually something I have done a couple of times, what I usually do is drill and tap a side plate to get vacumn, thread on a 90 degree nipple, and run a hose to the vacumn side of a modern fuel pump which I attach at any convient place on the motor. It works quite well, and allows the usage of a modern fuel tank.
 
RandyJ

RandyJ

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

Thanks guys... one thing I was wondering about is the small hose running from the block under the intake which goes to the tank. I do not know if this is a pulse line or if it only produces positive pressure to the tank???
 
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Walker

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

Its a pulse line and I'm fairly certain that hooking it to the pulse fitting on the fuel pump should be all you have to do.
 
RandyJ

RandyJ

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

Thanks... maybe I should get another fuel pump off of a smaller motor and try all new hoses. If I can get to the warehouse today I may buy a new fuel pump...at least I can buy wholesale and that will help lots.
 
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Paul Moir

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

That is the pressure line. It does not pulse and will not operate a fuel pump. You need to remove one of the check valves in the intake, and block the other to obtain a pressure pulse drive.<br />The 15hp (19.94 CID) engine doesn't have transfer port covers. So that's the most practical place to get your pressure pulses without having to disassemble the block to clean out shavings, etc.
 
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R.Johnson

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Sep 24, 2003
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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

Get a fuel bypass cover from a later 18, 20, 25, and bolt the fuel pump directly to that. Unscrew the nipple from the manifold to the fuel tank, and screw in a 1/8 pipe plug. The single line fuel recepticle will bolt right in where the double line recepticle is located, and you are good to go.
 
RandyJ

RandyJ

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Re: retro-fit fuel pump 1956 SeaHorse 15 h.p.

I think I'll look at something similar and see if I can do the bolt on thing. If I had a clue where the check valves in the intake are I'd give that trick a shot. I've got a 1972 20 hp Johnson I can look at and maybe "barrow" parts for this experiment.... I was trying to put an electric starter on that motor with no luck.
 
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