Help me figure out how to install one of these fuel bungs?

[TheFieryMan]

The EFI conversion is getting close now. I discovered that the fuel lines which run to the petcock are way too small so I picked up some of these bulkhead connectors but I'm not sure how I'm going to tighten up the nut on the inside. I'm running one for output and one for return. I'm planning on just putting them near the bottom of the tank.

Any tips on how I can install them?

IMG_3168.jpeg

[dontwantapickle]

Why the bottom of the tank?
seems like up near the sending unit hole would be the easiest.

[cfairweather]

I agree with DontWantToPickle; however, I have another idea for you. Use the original petcock location. Drill out the existing holes to a larger size and then tap them for larger metal fittings (Not the ones you have already bought). The steel is strong and thick enough to allow this where the petcock is mounted. Use one hole for the intake and one hole for the return. You can add steel tubing from the primary fitting to the bottom of the tank, just like the original design, except the tubing will be larger in diameter. Just remove the original tubes. Whatever you do, be careful and make sure the tank is completely clean, dry and has no gasoline smell before you drill.

[TheFieryMan]

Why the bottom of the tank?
seems like up near the sending unit hole would be the easiest.

Once the fuel level dropped below 80% full it wouldn't pick up any fuel. I'm not running any pickup tubes inside the tank. Just a bung. It has to go on the bottom where the fuel is.

[TheFieryMan]

I agree with DontWantToPickle; however, I have another idea for you. Use the original petcock location. Drill out the existing holes to a larger size and then tap them for larger metal fittings (Not the ones you have already bought). The steel is strong and thick enough to allow this where the petcock is mounted. Use one hole for the intake and one hole for the return. You can add steel tubing from the primary fitting to the bottom of the tank, just like the original design, except the tubing will be larger in diameter. Just remove the original tubes. Whatever you do, be careful and make sure the tank is completely clean, dry and has no gasoline smell before you drill.

What you're suggesting is the ideal and I would love to do it that way. The obstacle is how to add the metal tubes inside the tank. I don't really want to remove the tank and I think the only good way to do this is to cut the tank open and then reweld it. I'm not planning to go that far into it. A bung (and return) at the bottom is going to be the simplest way to make it work.

What I really wanted to do was replace the whole sender unit with a pump / sender unit but I can't find one that would fit.

[cfairweather]

Doing it your way will be the most difficult by far and I don't think you will be successful because the metal is not thick enough at the bottom. Adding tubes would be very easy to do. Good luck.

[3KidsinAustin]

My 85 Limited had its outgoing fuel nipple at the bottom of the tank, cocked at a 90 to the externally mounted petcock. I searched through my old pictures and couldn't find any good ones of the bottom of the tank. Not sure how similar the GL1100 to GL1200 tanks are, but could you remove the fuel sender, drill a hole in the bottom of the tank, then run your fuel connector into it and bolt it down with a long ratchet extender? Check clearance first with the exhaust and rear subframe, but that is probably how I would do it. It might be tough to wiggle that into position with the tank mounted on the bike though. Then, could you route the return line through the original line to the petcock?

I'd consider a 90-degree elbow to shoot the main fuel line off to the side to the fuel pump/petcock, if possible.

[cfairweather]

I thought of one more idea for you. The GL1000 has a drain hole bolt plug. You could remove it and install the bung in that threaded hole.

[theailer]

Yet another idea, the one that I will be using, is a return less system, which I think is pretty elegant as well.
So you would only need to use the existing pet cock and a small pcb which in turn send pulses to the fuel pump to keep it at exactly 43,5PSI or what setting you want to use. This will also result in less power draw on your power system as well since the pump will only run at a fraction of the speed compared to a return system where it is running on full power all the time.
https://www.madhu.com/content/Main/FuelPumpController

I think this is a perfect match in order to bring the old beast into the modern age

[dontwantapickle]

Why the bottom of the tank?
seems like up near the sending unit hole would be the easiest.

Once the fuel level dropped below 80% full it wouldn't pick up any fuel. I'm not running any pickup tubes inside the tank. Just a bung. It has to go on the bottom where the fuel is.

When you figure it out... Post Pics.
I'm interested in seeing how it all turns out.

[gltriker]

I would strongly advise you to NOT plumb into your bike's fuel tank below it's fullest fluid level with that bung
fitting. and " oil- resistant PTFE washers."

Do you even know what the fitting's hex nut torque figure is??
Gasoline fires are extremely expensive in more ways than one. (Skin grafts are Very EXPENSIVE and PERMANENT!!)

Remove the fuel tank and create safe, reliably leakproof, fuel tank- to-efi supply and return line circuits.
Inquiring in an online Forum for suggestions is fraught with liability.

Personally Consult with professional fuel system designers and fabricators.

Done