520H fuel pump

[Mjh 33]

I just purchased a facet fuel pump for my 520H. Install instructions say to mount it near bottom of fuel tank. But no place to mount it back there. Supposedly if mounted above tank the fuel will drain back into tank after not been run for a while. So I've mounted where original one was. Now planning to install an inline shut off valve at bottom of tank. So can stop fuel from back flow when not using. Hopefully this will keep pump from running dry and burn out? Planning to run hot wire to hot side of ignition coil so it only runs with key switch on. Will have an inline fuse in it so can pull fuse to stop power to pump in case need to have switch on to check something else electrical. Will this set up work? Haven't cranked it over yet. Waiting for a Andrews ignition coil to show up. Want to install this first. What's anyone's opinions on switching over to an electric pump?

[953 nut 55,859]

Your wiring sounds fine, but you can make a small frame mounted bracket to bolt it to like this.

[WVHillbilly520H 10,374]

29 minutes ago, Mjh said:

I just purchased a facet fuel pump for my 520H. Install instructions say to mount it near bottom of fuel tank. But no place to mount it back there. Supposedly if mounted above tank the fuel will drain back into tank after not been run for a while. So I've mounted where original one was. Now planning to install an inline shut off valve at bottom of tank. So can stop fuel from back flow when not using. Hopefully this will keep pump from running dry and burn out? Planning to run hot wire to hot side of ignition coil so it only runs with key switch on. Will have an inline fuse in it so can pull fuse to stop power to pump in case need to have switch on to check something else electrical. Will this set up work? Haven't cranked it over yet. Waiting for a Andrews ignition coil to show up. Want to install this first. What's anyone's opinions on switching over to an electric pump?

Unless you have a rear clevis hitch/lift you could mount it under the seat pan on the trans/seat frame also your fuel tank should already have a shut off valve where the line connects, I like the electric fuel pump on my street rod but it has bigger battery/alternator vs the relatively low output of the Onan but you shouldn't have to worry about long cranking times to get fuel to the carb, eBay and Amazon have cheap replacement pulse pumps for the Onan,almost forgot you did block off the vacuum line that originally went to the pulse pump if not you'll have a vacuum leak/surging,  Jeff.

Edited April 9, 2018 by WVHillbilly520H

[Sarge 3,463]

If you want to use a check valve, place it after the pump. This will hold the fuel back to the tank well enough for the pump to keep it's prime and not force the pump to pull fuel through the valve. Electric pumps are far better at pushing than creating a vacuum to pull fuel into their valves, if it gets a block of air it can burn out. Absolute best way to route one is with a bypass line so it can circulate fuel through it while running, but that involves adding a bypass type fuel filter and having a way to run a return line into the tank. Not an option on most of our equipment but I do run my D180 with a tee below the fuel tank to allow the pump to circulate fuel. This way, the pump runs cooler and at a much less pressure demand, extending its lifespan.

 

Sarge

[Kurt-NEPA 755]

I'm a big fan of electric fuel pumps, but mounting them is a real PITA.  When I put them on my 520H's I put them under the seat.  You loose the rear hitch lift that way.

 

 

For wiring, I came off the unused R terminal on the ignition switch to fire a relay.  Only problem with this approach is the pump is off while the engine is cranking.

 

[953 nut 55,859]

37 minutes ago, Kurt-NEPA said:

I came off the unused R terminal on the ignition switch

The "R" terminal should be going to your voltage regulator. Is your battery charging?

[Kurt-NEPA 755]

5 minutes ago, 953 nut said:

The "R" terminal should be going to your voltage regulator. Is your battery charging?

On the 520H, the "R" terminal is not used.  From the demystification guide

 

[Sarge 3,463]

There has to be a better way to route that fuel line and not lose the use of the rear lift. Should be able to move the pump further downstream since it's well below the tank - it would still do the job.

 

Sarge

[Kurt-NEPA 755]

43 minutes ago, Sarge said:

There has to be a better way to route that fuel line and not lose the use of the rear lift. Should be able to move the pump further downstream since it's well below the tank - it would still do the job.

 

Sarge

 

I tried every place I could find.  There aren't many options. 

[WVHillbilly520H 10,374]

8 hours ago, Sarge said:

There has to be a better way to route that fuel line and not lose the use of the rear lift. Should be able to move the pump further downstream since it's well below the tank - it would still do the job.

 

Sarge

 

7 hours ago, Kurt-NEPA said:

 

I tried every place I could find.  There aren't many options. 

Maybe on the inside of frame near the rockshaft but there too looks very tight, as I have a pic above with the seat pan removed on 1 of my 520s, Jeff.

[biggin 36]

I know it’s a year old thread but...

I’m getting ready to hook my facet fuel pump and everyone is correct about not much room to mount it but here’s where I’m putting mine, should still allow me to use use the rear lift. Pump is not mounted yet, this pic is just the mock up. 

Edited May 9, 2019 by biggin

[biggin 36]

I ran all new fuel line and I still need to route the wiring up front to my relay. Is it the yellow wire on my ignition switch plug that I need to tap for the relay, I believe I read that somewhere but don’t recall. 

[biggin 36]

Never mind, I see the “R” location on my ignition switch is open, I just need to find the correct connector to fit in the ignition switch plug 

[biggin 36]

Does anyone know what the correct connector for this style of plug? 

[Lee1977 6,808]

I guound out the mounting bar on a cheap Chinese pump and mounted it where the other pump was.  I also used the R terminal with a 5 amp fuse and the ground back the the battery ground. Also added an on/off switch to the dash. 

I have a question for 520 owners. All the drawing shown for the 520 I have seen in the manuals show the key switch on the right side. Mine is on the left side. I realise the panel could be switch but the decales are all there.  Where is your key switch located? 

I added my fuel pump switch on the right .

Edited May 14, 2019 by Lee1977

[biggin 36]

Mine is on the left as well. 

[biggin 36]

Finally got back to work on the tractor. I have the pump mounted and new fuel line and wires run, just have to finish wiring it up and try it out. 

[biggin 36]

Finished the wiring and all is working. I ended up using a relay, I don’t think I really need it but I had it already and decided to use it. Definitely starts quicker. Apparently I didn’t get the governor hooked up correctly so I need to work that out. 

Edited June 17, 2019 by biggin

[TJ3 1]

Old, but useful thread.

 

I'm installing an Airtex E8016S electric fuel pump. 

I see some of you say to connect to the R terminal on the ignition switch, but the Airtex paperwork says "For safety reasons, it is recommended an Oil Pressure Safety Switch be installed. This will prevent engine damage and reduce the chance of fire in the case that the engine stops without the ignition switch in the "off" position.".

 

So should I trigger my relay off of the oil pressure sending unit? To me, it seems that this wouldn't work, as oil pressure won't build to an appropriate level, until and unless the engine is actually running, not just cranking. 

Or am I off in my line of reasoning? 

 

Also, on the question of having it below the tank is required to gravity-prime it, the paperwork also says "Place the pump and bracket assembly as near to the bottom of the tank as possible, but never more than 24 inches above the top of the tank.". 

 

Thanks! 

 

Jack

Edited August 1, 2020 by TJ3

[Kurt-NEPA 755]

Getting the feed to the pump from the oil pressure switch will kill the pump if your engine stops.  It would be a safety measure.  So it is your choice.  If you have disabled you seat switch, it wouldn't make much difference.  So do what you feel make sense.

 

A gravity feed to the pump really helps.  I highly recommend it.  When you turn on the tractor, you pump will immediately supply fuel to the carburetor.  If the pump is higher, then there will be a delay at best and maybe the pump will never get fuel to the carb.  Again, your call.

 

[Mjh 33]

I ran hot wire to plus side on ignition coil. And negative to battery when I upgraded to a facet pump on my 520H. Pump will run continues when ignition switch on. Just give full choke a little throttle and it’s running immediately. Could install inline switch to hot wire so can kill pump manually. I just installed an inline fuse on mine. Works for me.