Electric Fuel Pump

[CGH]

Newbie to posting on this board. but I have been reading the post here for years. I have learned quit a lot here and hope to learn more

I Have a 1956 Evinrude 7520 7.5 HP outboard. It used the pressure tank and I have one that works fine.

My question is this. If I install a inline Electric Fuel Pump, and pump fuel to the motor will it run.

I will be using a plug to plug up the pressure line (marked air). I have devised a way to turn the pump off automaticly when the engine is not running. And a by pass to turn the pump on only while starting

I have not yet invested any money in this plan.

Please not looking for replies like...
"If you have a working tank why are you wanting to install Electric Fuel Pump"
"this is not safe and if your motor shuts off the Electric Fuel Pump will still be
pumping fuel"

THANKS in advance

 

[wilde1j]

Re: Electric Fuel Pump

Sure, it will run.

 

[CGH]

Re: Electric Fuel Pump

Thanks. My brother wants the pressure tank for his 10 hp. I would rather used the plastic tanks from wally-world

 

[tashasdaddy]

Re: Electric Fuel Pump

if you have a failsafe method of turning the pump of even if the motor stalls. not just turned off by a switch. but it is really not recommended.

 

[tx1961whaler]

Re: Electric Fuel Pump

Make sure the fuel pressure is set right. Set it as low as it will stand at WOT. The float/needle valve in the carb will only shut off a certain amount of pressure. I'm assuming that you are going to use an adjustable pressure pump........
I'd retrofit a vacuum fuel pump on it for a single line conversion, but to each his own....

 

[CGH]

Re: Electric Fuel Pump

the three pump(s) that I'm looking at have a rating of 2 thru 7 psi.

One is adjustable from 2 to 5 psi
One is adjustable from 3 to 7 psi
One is fixed at 3.5 to 4 psi

I think that the motor supplies 4or 5 psi but not sure.

 

[F_R]

Re: Electric Fuel Pump

The pressure tanks do run at 4-5psi.

 

[rjezuit]

Re: Electric Fuel Pump

The mechanical vacuum pumps are a better and safer solution, plus you will not be dead in the water without a bettery or if the battery goes dead. Rick

 

[Silvertip]

Re: Electric Fuel Pump

Please re-think this! Electric fuel pumps on nearly every engine in existance today has a fail safe device wired into the circuit so if the engine quits, so does the pump. It may be the ECM or an oil pressure switch that kills the pump. On your outboard you have no way of killing the pump except for flipping a switch. In an emergency people tend to get very rattled and should you rupture a fuel line on the engine, that fuel pump can force feed a very serious fire. This is simply not a good plan when there are much better and safer solutions.

 

[tx1961whaler]

Re: Electric Fuel Pump

Silvertip - In his first post, he said that he did not want any common sense replies. I assume that he read the other forum posts strongly warning against using an electric pump on an outboard, since he knew what the replies would be.
This is where I let Darwin take over, and hope no bystanders are taken out with him.....

 

[coolguy147]

Re: Electric Fuel Pump

if u really wanna do this plan please tell us why u want to? oh and my idea is make the fuel pump switch a kill switch u know? not sure how to be done its and idea

 

[CGH]

Re: Electric Fuel Pump

This is my setup for a Safety switch.

My brother wants the pressure tank for his 10 hp. I would rather used the plastic tanks from wally-world

 

[Xcusme]

Re: Electric Fuel Pump

CGH,

You know what....one of the nicest and best things about older outboards is their simplicity. Simple designs, basic fuel and ignition systems. This is why I, like so many others , here on iboats, like the 'older stuff'. These vintage motors are easy to work on, simple to operate and are built on a legacy of being dependable and reliable. You own such a motor, it's been around longer than a lot of the members , here on this board. That said, please listen to the sage advice offered and re-think your electric fuel delivery plans. Will your design work? Sure, why not...it's simple enough on paper, but it's not without it's risks and costs. The point is, by keeping things simple, it will be more reliable without risking the real danger of fire and maintenance problems previously mentioned. The dual to single line vacuum conversion system is a proven solution and it's cheaper to boot. Properly installed, you'll soon forget it's there silently and safely doing it's job. Keep that 'ol girl simple, and dependable, you'll thank yourself later when you're a long way from home and storm clouds are brewing. A simple pull of the rope will send you on your way.

 

[F_R]

Re: Electric Fuel Pump

This is my setup for a Safety switch.

My brother wants the pressure tank for his 10 hp. I would rather used the plastic tanks from wally-world

Your safety device won't work. There is a one-way check valve in the motor's air line. Air flows out but can't flow back into the motor. If the motor stops, air pressure is held in the line. You could add a bleed orfice to relieve the pressure, but that would bleed off fuel also...making a mess and another possible fire hazard.

Before you think of it, removing the check valve won't work either because ahead of the valve there are pressure/vacuum pulses, not just pressure.

Personally, I think the hazard issue with an electric pump are blown way out of proportion. Any system is a hazard if a line breaks. But I'd still go with a pulse operated pump if it were me. In fact I am doing one right now. Modern, simple, and reasonable cost.

 

[CGH]

Re: Electric Fuel Pump

Your safety device won't work. There is a one-way check valve in the motor's air line. Air flows out but can't flow back into the motor. If the motor stops, air pressure is held in the line. You could add a bleed orfice to relieve the pressure, but that would bleed off fuel also...making a mess and another possible fire hazard.

Before you think of it, removing the check valve won't work either because ahead of the valve there are pressure/vacuum pulses, not just pressure.

Personally, I think the hazard issue with an electric pump are blown way out of proportion. Any system is a hazard if a line breaks. But I'd still go with a pulse operated pump if it were me. In fact I am doing one right now. Modern, simple, and reasonable cost.

Darn foiled again!!!

I guess I'll be using the pressure tank again next season. Just how hard is it to convert a 7520 to use a pulse operated pump?

 

[F_R]

Re: Electric Fuel Pump

Pretty simple if you have one of my adapter plates....or make your own.