electric fuel pump

[dempsey 1]

Hi, I was wondering if you can use an electric fuel pump on an outboard motor?
Thanks,Dempsey

 

[5150abf]

Re: electric fuel pump

The general concesus around here is no, it is a really bad idea because it is always pumping fuel where the original pump only works when the engine is running and most electric fuel pumps are designed to pump way more fuel than the engine needs.

They also work at a higher poressure than the original pump and gas can get past the needles and cause other problems, it is best to stick with the original pump.

 

[Silvertip]

Re: electric fuel pump

The real reason for NOT doing this is that if the engine stalls or fails to start and you don't turn the key off, the fuel pump continues to run and can load the engine up with fuel. You then try to start the engine again and you hear KABOOM -- which is followed by a trip to the hospital. Fuel injected two stroke and four stroke engines have an ECU that knows when the engine is running so it controls the fuel pump. Four strokes can do this with the oil pressure switch as well. Carbed two strokes have neither of these features so there is no simple way to control the pump. And you cannot ignore this issue by saying I will always turn the key off because the time will come when you don't. It is simply not safe to do so unless you incorporate a safety (engine off) circuit.

 

[Frank Acampora]

Re: electric fuel pump

And, the basic design of pulse fuel pumps as used on outboards has been in use for years on a variety of engines including lawnmowers chainsaws, and weedwhackers. It is simple and proven, easy to repair, and relatively trouble-free. Why fix something that 'aint broke?

The repair parts cost 5 bucks and an electric pump costs upwards of 35. Do the math.

 

[cajunmerc]

Re: electric fuel pump

For most motors no, i run a holley blue 110gph on my 2.4 bridgeport, carb, these motors rev so high and fast that there is no pulse pump on them,nor designed to work for them, they are very easy to regulate, i use a 7-9 lb regulator with a return port to the fuel tank. There is no hazard issues and both mine are bassboat motors,unless you have a motor that consumes 110-130 gph, you dont need one.

 

[Silvertip]

Re: electric fuel pump

A carbureted engine without a safety shutoff for the electric pump is still a potential bomb regardless how it's rigged. A float that has failed to shut off the inlet needle can fill an engine with fuel. A leaky fuel line or fitting somewhere in the system will spray fuel engine off and key on (again -- in an emergency you may not remember to turn the key off to kill the pump -- regardless how "with it" you think you are). That is especially true if someone else happens to be operating the boat.

 

[Texasmark]

Re: electric fuel pump

I had a tower and ran it at 6000 rpm's at WOT. I would run it for awhile and it would run itself out of gas. I thought an electric fuel pump was the answer and in short it wasn't. I wound up rerouting my fuel lines and making the lines as short as possible and solved the problem. One of my problems was it was in the early years of Merc having oil injection and the oil was injected into the gas from a separate oil tank on the way from the gas tank to the engine. This probably had something to do with it.

Mark

 

[metriccrescentwrench]

Re: electric fuel pump

Well...... I know running an electric pump on outboards is a touchy subject around here, however.... if you're bound and determined to do it -

Have your fuel pump relay wired through the kill switch (as is mandated in all outboard racing classes)

There's a fuel pump relay available from VW which senses ignition pulses and turns off with the engine. If you search online several people have adapted it to work with outboards.