Aux fuel pump

[Justin]

I'm in the process of mounting up my tour tank to the FJR. I want to mount it pretty low so I can open my tailbag, so I'm most likely going to need a fuel pump. Suggestions wanted for which pump. Something simple and reliable.

 

[FJRay]

I made my own aux tank and one of the requirements was that I could open the top box. It gravity feeds just fine and holds 4.3 gallons.

 

[Canadian FJR]

For gravity feed, it only has to be slightly higher than the bottom feed to your main tank, yours looks pretty close. You may not need an aux. pump.

Canadian FJR

 

[Justin]

I can actually bring it up a few inches, so I might be OK with gravity feed. Same tank I use on my Busa, but it sits higher on that bike in relation to the main tank. Once I get it mounted up and plumbed to the main tank I'll see how it flows.

 

[dcarver]

I can actually bring it up a few inches...

Tyler, what say you?

I have a gravity feed tank with squeeze bulb and valve arrangement so I can pressurize the top of the tank to force the gas into the main tank more quickly. Soon though, I'm going to toss that setup and put fuel pp on it.

 

[Shane]

I can actually bring it up a few inches, so I might be OK with gravity feed. Same tank I use on my Busa, but it sits higher on that bike in relation to the main tank. Once I get it mounted up and plumbed to the main tank I'll see how it flows.

From the looks of the picture above, you should be just fine with gravity feed. The Main tank will have to be pretty low to accept the last of the aux tank contents, but that's true on mine as well. Makes for a longer reserve!

Gravity being the law and all, and liquid finding it's own level and stuff, I'm pretty sure that the only requirement for full transfer is that the bottom on the aux tank needs to be only slightly higher that the bottom of the main tank for proper transfer. Extra elevation may speed things up, but is not necessarily better.

All the best,

Shane

 

[Warchild]

Gravity being the law and all, and liquid finding it's own level and stuff, I'm pretty sure that the only requirement for full transfer is that the bottom on the aux tank needs to be only slightly higher that the bottom of the main tank for proper transfer. Extra elevation may speed things up, but is not necessarily better.

This is an ill-advised approach for Justin, because he typically attends Western endurance rallies.... a slow transfer rate would be a huge issue in some events. He will likely end up outrunning his fuel supply... it's happened before, to more than a few folks.

For purposes of this upcoming Endurance event next month, Justin either needs to raise the tank as much as practical, or bite the bullet and go with an electrical pump until such time as he can fab up a proper rack that raises the cell a good several inches, but still allows him to fully open the topbox.

 

[karstenp]

I have a taildragger style aux tank and use the NOS 15760 fuel pump https://performanceparts.com/part/NOS/15760NOS. About 70,000 miles and no problems. I would recommend the pump if you decide to install one. The pumps fits nicely at the back of the bike. Refer to pics on my Blog (link below) if interested.

 

[Justin]

Gravity being the law and all, and liquid finding it's own level and stuff, I'm pretty sure that the only requirement for full transfer is that the bottom on the aux tank needs to be only slightly higher that the bottom of the main tank for proper transfer. Extra elevation may speed things up, but is not necessarily better.

This is an ill-advised approach for Justin, because he typically attends Western endurance rallies.... a slow transfer rate would be a huge issue in some events. He will likely end up outrunning his fuel supply... it's happened before, to more than a few folks.

For purposes of this upcoming Endurance event next month, Justin either needs to raise the tank as much as practical, or bite the bullet and go with an electrical pump until such time as he can fab up a proper rack that raises the cell a good several inches, but still allows him to fully open the topbox.

I will be making a proper rack for it, and getting it as high as possible while still being able to open the trunk reasonably. I should have it done this weekend, and I'll be able to see how fast the fuel flows. If it's at all borderline I will add a pump in. I prefer to keep things as simple as possible - but as you say, running at western velocities on a bike pushing this much air sucks gas pretty quick.

 

[doug5551]

On my gravity feed, I wait till I am at two bars, then throw the lever.

That has worked perfectly for 80k miles.

 

[dcarver]

This tank, with 1/4" hose, flows fuel at a rate equal to consumption when running 70 mph.

The feller on KrZy8 is Brodie, a forum member.

I use a rubber squeeze bulb and a 2 way ball valve that either vents the tank or isolates the tank. When isolated, the squeeze bub applies pressure to the gasoline top, forcing fuel into the main tank at a much faster rate. It's kind of a PITA, it takes 20 squeezes approx every 3 or 4 minutes over maybe 5 'cycles' to get the aux tank emptied.

My normal routine is to burn main tank to 3/8 or 1/2 full, open gravity feed then just ride. Having a lower level in main facilitates gravity flow. Then, if needed, I can use the pressure blanket to push the remaining fuel from aux to main tank.

Next thing for me will be a pump with delay timer relay in circuit. Close the switch, the pump will run for some time period. Maybe 3 minutes would be a good start? That way, if when fatigued or just being a dumb ass, the main tank won't be overfilled from accidentally leaving the pp on too long.

Good luck!

 

[Justin]

So, my friend who is fabbing up the mounting bracket for came by, and we measured everything out. Once done, the Aux tank will be a good 5-6 inches above the bottom of the main tank. I'm thinking this should be plenty for a good flow. I'll update next week when it's all done, and I've had a chance to test it.

 

[DaJuice]

I'll offer my advice for consideration if you run into problems with slow transfer with gravity feed. I did the ballectomy shortly after I put the fuel cell on my 1st bike since I was having a hard time getting fuel to gravity transfer when it was hot. I have not done it yet on my new bike and have noticed when I forget to close the valve on my cell and leave it sit in the sun the gas will actually push out the main tank and back to the cell. I parked it at work one day with 6 bars and when I came back out it only had three. That never happened with my 1st bike after the mod and my 1st and 2nd bikes are nearly identical (both 08's). It did transfer eventually and I got my 400 miles out of the fill but it is definitely not as fast as the original bike with the ball out.

The link is a solution to a different problem but it help

Linky

Here is a pick of the cell on the bike so you can see how much elevation I had.

 

[Shane]

Gravity being the law and all, and liquid finding it's own level and stuff, I'm pretty sure that the only requirement for full transfer is that the bottom on the aux tank needs to be only slightly higher that the bottom of the main tank for proper transfer. Extra elevation may speed things up, but is not necessarily better.

This is an ill-advised approach for Justin, because he typically attends Western endurance rallies.... a slow transfer rate would be a huge issue in some events. He will likely end up outrunning his fuel supply... it's happened before, to more than a few folks.

For purposes of this upcoming Endurance event next month, Justin either needs to raise the tank as much as practical, or bite the bullet and go with an electrical pump until such time as he can fab up a proper rack that raises the cell a good several inches, but still allows him to fully open the topbox.

Makes sense.

Pictures of a gravity-only Joe2Lmaker cell (and the elusive Tanji alongside at Mount Evans).

All the best,

Shane

 

[Justin]

Thanks for the pics and thoughts folks. I'll post up some pics when mine is done. Hopefully I won't need a pump, but we'll see. Like I said above, the tank will be a good 5 inches above the bottom of the main tank, so I think it should be good.

 

[bgross]

At the IBR checkpoint in Sacramento, one of the FJR riders (sorry, I don't remember who) was trying to diagnose his problem:

He'd turned the valve on the aux tank to transfer the contents to his main tank. Fortunately, someone alerted him to the fact that gasoline was streaming (dumping) out the aux vent hose by the license plate.

His best guess (when last i saw him) was that the heat was pressurizing the main tank and the vent wasn't allowing properly functioning - instead, it was pushing the pressure (and fuel) back to the aux. and then causing it to jettison.

Seems like there ought to be a check valve?

 

[Ignacio]

Seems like there ought to be a check valve?

Or just remember to not turn on aux tank if its hot.

 

[Justin]

Heading down to my friend's place tomorrow to do some drilling and welding . Will have the mount completed sometime during next week. Then we'll find out if I need to a pump.

 

[dcarver]

Weird. None of the icons at the top are active.

Justin, it sounds like you know what you're doing, so not sure how much this link will help. Just in case, though, here's my write-up of when I did mine.

https://candybuttorg.ipage.com/cba/node/90

D