Electric fuel pump conversion

[boat_beginner]

I have a 1973 85hp evinrude, on which the furl pump crapped out on me. I was going to replace it with an electric fuel pump. I can get the electric for half the price of the factory pump.
Now, my question is, what PSI should the pump be pushing? I called a local boat shop, n they recommend 1-2 PSI. They said more than that, the pump will force fuel through the carberatur at a much faster rate than the motor can burn, and it will run really rough or not at all.
I'm having a hard time locating a pump with such low PSI. I see them for around a 3-5 PSI range, but not lower than that.
Also, what about the flow rate? A local parts store has a pump that pumps 28gpm(or GPH?), can't remember off hand, but it don't mention the PSI behind it. Which number should I be looking at, the flow rate or the PSI? N what would be an ideal number?

 

[metriccrescentwrench]

Re: Electric fuel pump conversion

Have you thought about how your gonna' turn off the electric fuel pump in case of an emergency/upset? I'll tell ya' what, if sh%%% hits the fan you're not gonna' be thinking about reaching over and turning off a switch, so that's not a valid solution. The thing with electric fuel pumps is that on a 4 stroke engine there's the oil pressure switch which only allows the fuel pump to run when the engine's running. With a 2-stroke we don't have that, so if the engine hiccups and catches fire, for instance, the electric pump will keep pumping fuel while you're running around trying to get the fire extinguisher out of it's holder and figgerin' out how to get the pin out etc.

At a very minimum find an emergency kill switch with a second set of contacts (or run the kill switch through a relay) so that the safety lanyard will kill the fuel pump (and wear the lanyard when you're boating).

Now then, 28 gph ought to be more than enough for your engine. As far as pressure, you need to find a factory manual for your engine and see what it's supposed to be. I had a 200 that I had rigged for an electric pump (and taken proper precautions to be able to shut the pump off in an emergency), the spec for that engine was around 4 - 5 psi as I recall, but yours could very well be different.

 

[boat_beginner]

Re: Electric fuel pump conversion

Very good point with using a kill switch. My plan was to wire it to the key ignition, so when the key is in the "ON" position, the fuel pump is on, and it will turn off with the key. The thought behind that is so I do not forget to turn it on/off when starting/turning the motor off.

 

[octanerocks]

Re: Electric fuel pump conversion

If your fuel pump is the same that's on a 78 115 hp, u can get a rebuild kit for the pump for much less than an electric pump. Safer too

 

[octanerocks]

Re: Electric fuel pump conversion

Never mind looks like that pump has two outlets, I don't know if that kit would work

 

[boat_beginner]

Re: Electric fuel pump conversion

Never mind looks like that pump has two outlets, I don't know if that kit would work

The pump on there now has 3 outlets/inlets. I researched it online and it seems that they are not the friendliest to rebuild, that its better/easier to completely replace the pump. That's when I got the idea of an electric pump instead, when I seen the price of them.
Now I can't seem to find the correct PSI electric to put on it.

 

[brianc31525]

I have a 1973 85hp evinrude, on which the furl pump crapped out on me. I was going to replace it with an electric fuel pump. I can get the electric for half the price of the factory pump.
Now, my question is, what PSI should the pump be pushing? I called a local boat shop, n they recommend 1-2 PSI. They said more than that, the pump will force fuel through the carberatur at a much faster rate than the motor can burn, and it will run really rough or not at all.
I'm having a hard time locating a pump with such low PSI. I see them for around a 3-5 PSI range, but not lower than that.
Also, what about the flow rate? A local parts store has a pump that pumps 28gpm(or GPH?), can't remember off hand, but it don't mention the PSI behind it. Which number should I be looking at, the flow rate or the PSI? N what would be an ideal number?

I have a 77 85hp Johnson and im having issues with the replacement pump being through 5 different revisions of this pump they say it's the same but it is bigger than the stock pump. And there aren't any rebuild kits available. 5 revisions might be why. I have 6 fuel pumps that would work if they did sell a rebuild kit. Was thinking about going the route you are electric. Any follow up on this?

 

[Chris1956]

Electric is a real bad idea, unless wired with a proper relay driven off the stator or something else that goes dead if the engine stalls. Otherwise, fuel will keep pumping, even if the engine stalls, possibly filling the bilge or cockpit with gasoline.

Gee, fuel pump rebuild kits are real cheap and easy to get. Get the serial number of your motor and see if you can look up the proper kit by serial group.

 

[Crosbyman]

this thread is 11 years old.... best to open a new one reviving old ones is not recommended.

the problem is hopefully solved since 2013

in any event those pumps are all over the place incl Amazon. Any proper sized pulse pump should work space permitting

Amazon.ca

 

[racerone]

About the only thing that can go wrong with the pump is a ruptured diaphragm.----Easy $6 .00 fix.----Repeat--- it is easy.----Or if the pump does not receive a good PRESSURE pulse from the crankcase it will not work.-----Or if there is an issue with fuel line and pick up tube inside the fuel tank.