Electronic Fuel Pumps - KT-17 & Mag 20

[mpatterson]

Ok, So what is the REQUIRED PSI for electronic fuel pumps on these engines? I see the one Kirk sells, and the one that Digger sells..... they are different PSI ratings if I understand correctly? What is the range you need for these engines when replacing the original mechanical type pumps? I'm guessing there are other specifications that the pump needs to operate properly?

Other dumb question... you can test the old mechanical type pump by just disconnecting it from the carb and cranking engine over right? Because if that's the case - I know that mine is shot! I changed the fuel filter (Thanks Digger) and gas runs freely from the tank through the filter and out the end of the hose. Hook it to the pump and crank the engine and it doesn't happen! Just want to make sure there isn't some sort of fancy vacuum or something created when hooked up to the carb from the mechanical pump.

I've pretty much had my fill of the old mechanical type ones. I've given them about a dozen tries and I'm still having issues with them - new or used! OMG!

 

[snicklas]

My opinion would be 5 PSI or less. The one Dave sells says 1-2 PSI. I know they make a similar one that is 5ish PSI (in a quick look I didn't see the one on CCS). But you are simply needing a "lift pump". Something to move fuel from the tank up to the carb. You don't want too high a pressure, or it will "blow" the float needle open and cause the carb to flood/fill full of fuel. Same idea at the "fuel pump" on a carburated vehicle engine. Most mechanical, arm on the cam, type fuel pumps run about 5 PSI. I would say one of the lowest PSI rated cube pumps would serve you well.

 

[mpatterson]

My opinion would be 5 PSI or less. The one Dave sells says 1-2 PSI. I know they make a similar one that is 5ish PSI (in a quick look I didn't see the one on CCS). But you are simply needing a "lift pump". Something to move fuel from the tank up to the carb. You don't want too high a pressure, or it will "blow" the float needle open and cause the carb to flood/fill full of fuel. Same idea at the "fuel pump" on a carburated vehicle engine. Most mechanical, arm on the cam, type fuel pumps run about 5 PSI. I would say one of the lowest PSI rated cube pumps would serve you well.

Sounds good to me. Thanks.

 

[mpatterson]

So I picked up my new pump today but I structure say I need a relay between ignition switch and the 3 amp fuse. What am I looking for in the way of a relay when I go to the store?
Was thinking of making a bracket to mount pump under and back from outlet on the fuel tank of 782 - should work and keep it cool as per instruction sheet saying to keep it under 140'F??

Where does everyone else mount their pumps when they install one of these electric ones?

 

[sleggett]

I mounted mine on the firewall of my 1811

 

[sleggett]

Wired to the hour meter, hot when ignition is on.

 

[sblunier]

Mike, 1-2 psi is all that's needed.

If you want to wire it with the relay, use diagram (for KT-17 with coil ignition) or you could just skip the relay and use fuse inline.....its only 1-2 Amps max

 

[digger]

 

[mpatterson]

View attachment 139038

Hey Digger, those small fuel filters I got from you, they are fine enough filter for these pumps right??

Thanks for wiring diagram and pictures guys, big help!

 

[sblunier]

 

[digger]

Hey Digger, those small fuel filters I got from you, they are fine enough filter for these pumps right??

Thanks for wiring diagram and pictures guys, big help!

Personally I'd use a large filter rather than the mini's.

 

[mpatterson]

Well, fired it up and the carb is leaking at the elbow for air cleaner. Will see today if it loose or what. Hope I didn't get a pump that was too powerful!?

 

[mpatterson]

View attachment 139043

Thanks Steve, appreciate the diagrams. Much easier for my pea brain.

 

[mpatterson]

Well, started it today with fuel turned on fully at tank. Fired it up and ran for 10 minutes, no leaks! So far that is. Fingers crossed it will continue to work, may just have to get another one for tha Mag 20 in the 982.