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Discussion Starter #1
My 99 LT was owned by an IBA rider who had apparently installed a fuel cell. I figured this out the first time I removed tupperware on the right side and saw the t-connector that had been installed on one of the two fuel lines under the tank (right side) and the fuel line that ran aft from the t-connector to a shut-off valve under the right side of the passenger seat.
So I am thinking installation of a fuel cell should be a breeze since the plumbing is already in place. I order a fuel cell from Sampson and the hardware kit for a gravity feed system (cause I heard bad things about relying on pumps).
Yesterday I receive my fuel cell and an e-mail from Sampson. Terry Smith is kind enough to e-mail some installation instructions that describe how to drill and tap right into the existing fuel tank, which apparently is how he thought I would be installing. I suggest I already have the plumbing in place to simply connect on one of the existing fuel lines and he suggests that won't work without a pump.
The instructions sounded like the drilling took place on a metal tank which I of course do not have.
So here I am, t-connector on fuel line, fuel line running to back of bike with shut-off valve, fuel cell delivered from Sampson, hardware kit from Sampson for gravity-feed set-up, and questions...
Can I tap into fuel line with gravity feed system or must I connect to tank? Is the line where the previous owner installed the t-connector the return line?
Should I/can I drill into the existing tank somewhere?
Should I exchange the gravity feed hardware for the hardware set that includes a pump?
I am relying on you all as I have found you to be much more responsive than Terry Smith at Sampson (not to knock Terry, just fact). A part of me wishes Terry might have discussed this with me after accepting my $700+ and before shipping what is apparently the wrong hardware. Well, what do I expect for $700+ these days?
 

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Didi
Snip>>__________________
>Can I tap into fuel line with gravity feed system or must I connect to tank?

You are currently plumbed into the low pressure return and that requires a pump

>Should I/can I drill into the existing tank somewhere?

The only metal part of the tank for gravity feed would be where the fuel lines connect, you may not have enough room to drill.

>Should I exchange the gravity feed hardware for the hardware set that includes a pump?

Yes

>I am relying on you all as I have found you to be much more responsive than Terry Smith at Sampson (not to knock Terry, just fact).

Terry is a nice fellow but , you are not the first with issues!

Go with fuel pump and carry a extra pump and switch since these are the only parts that can fail. They will last forever.

Take the time to measure the fuel cell volume, if you are concerned about IBA rides his cells have way more than 5 gallons as advertised. The other bummer is the position of the supply line does not empty the tank and about 12-14 oz remain.
Let me know how much fuel your cell holds and the volume remaining?
 

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I installed a fuel cell on mine three years ago, using a pump and haven't had any problems. I removed the fuel overflow canister that's under the top trunk and had plenty of room to put it there. I bought one from Napa for around $40 but I can't remember which one. I built my own tank and mounting system, which is all in one. Most people use a seat pan for mounting the tank which is a really good idea for ease of on and off. Mine uses the same mounting points. I'm only 3.5 gallons and I can go 420 to 450 miles, depending on speed but I wish mine was a little bigger but that's hind site. The only problem with a pump is you have to remember to turn it off and I have done that numerous times with no ill effect. I routed my hose to the top of the tank by the fuel fill and drilled and taped a 1/4" pipe hole and put a barbed hose fitting there. The tank was around a 1/4" thick at that point and threaded just fine. Good luck and ride until it's empty and repeat.

Bill
 

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Didi
What I did was get an upright 4 gal plastic cell from Summit Racing. I hooked my VENT hose from my tank to the fuel fitting of the cell with an inline fuel filter in between for extra filtering. Then I connected a vent hose from the cell vent to the vent hose that exits near the license plate also with another inline fuel filter. This may not be true gravity feed but as the fuel is used out of your tank, fuel is sucked out of your cell to replace the fuel in your tank and air is then sucked into your cell. Once all of the fuel is sucked out of the cell, your vent system to your tank will work as usual, air into first filter, then to cell and out to second inline filter and then into your tank. I mounted my cell on another rear seat pan that I had and bought my fuel fittings, filters and hose from local part store. (NAPA) Total cost including cell $165. Also your fuel gauge will register full until all of the fuel is sucked out of your cell and then will read normally. This system has worked great on a 100CCC ride and the Ride Around Texas (RAT).
 

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Discussion Starter #5
Love those answers!

They may not always be the answers we are looking for, but this community can be counted on for feedback!

Thanks Bill and EHutch for your ideas, some of the techniques you used should apply directly to my application. Had you gents had an article in the tech area I could have referenced, I might have had sufficient funds remaining for OTHER farkles this month. I guess that might be something I should do since I am right at the start of this "operation".

Special thanks to Pete for specific and detailed responses to my exact questions. I will follow up and let you know what my volume is once I get to that point. I met Rick Mayer two weeks ago at his place and he suggested having the same problem before an IBA ride and apparently was allowed to insert some sort of container inside the cell that "filled up" the excess volume. Your point is well taken and quite valid; one of the primary selling points, as advertised on the website, is the alleged fact that total volume will end up just "UNDER" 11.5 gallons...

I will take all your feedback for action. I am in the process of exchanging my hardware kit for a pump system and will ultimately connect to my existing fuel line/shut-off valve the previous owner connected to the return line.

I could not bring myself to destroy one of my two passenger seats so I ordered the kit for frame mount. I am pretty sure I will need to fabricate some sort of vinyl cover to fill in the gaps around the tank. Should I take lots of pictures of the entire process and post them somewhere on this website?

Thanks again,
 

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murray said:
Didi
Snip>>__________________
>Can I tap into fuel line with gravity feed system or must I connect to tank?

You are currently plumbed into the low pressure return and that requires a pump

--------------------?
There have been at least two people who have used gravity feed on the LT, plumbed into the return line, and it works just fine. The return line feeds into the tank at basically atmospheric pressure, so the fuel from the aux. tank, as long as it is higher than the stock fuel tank, will flow in. Not as fast as when pumped, but it will work. Caution though, you need a valve on it, or you will have fuel flowing out of the main tank vent when the main tank is full and there is fuel above that level in the aux. tank
 

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Discussion Starter #7
I was hoping to hear from my east county neighbor!

Thank you David, as always your suggestions are well thought out and logical. It makes sense that with a frame mount high on the back where the seat used to be, that fuel will feed when the main tank is low. So if I understand correctly, and based on all the discussion, once I open the valve and fuel feeds to the return line, I should see the fuel guage rise?

One additional question, where do I connect/run the vent line from the cell?
 

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MolenaarD said:
I was hoping to hear from my east county neighbor!

Thank you David, as always your suggestions are well thought out and logical. It makes sense that with a frame mount high on the back where the seat used to be, that fuel will feed when the main tank is low. So if I understand correctly, and based on all the discussion, once I open the valve and fuel feeds to the return line, I should see the fuel guage rise?
Correct
One additional question, where do I connect/run the vent line from the cell?
You want to be sure you get the vent line run down low, and away from the muffler. I would run it to the same place the cannister vent line is run, below the right side side case, near the rear. If you still have the cannister, that line should be visible when you look under the rear of the right side case.
 

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MolenaarD said:
I was hoping to hear from my east county neighbor!

Thank you David, as always your suggestions are well thought out and logical. It makes sense that with a frame mount high on the back where the seat used to be, that fuel will feed when the main tank is low. So if I understand correctly, and based on all the discussion, once I open the valve and fuel feeds to the return line, I should see the fuel guage rise?

One additional question, where do I connect/run the vent line from the cell?
I just did a search trying to find the posts where a gravity feed was used, and they must have been on the older group, which I cannot get to here at work. However, I did find posts on this group stating that others had trouble with gravity feed used on the return line.

I still think it will work, but you need a non spring loaded check valve to keep fuel from the return line from going into the aux. tank.

I will try to find the post where gravity feed did work when I get home tonight.
 

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MolenaarD said:
I was hoping to hear from my east county neighbor!

Thank you David, as always your suggestions are well thought out and logical. It makes sense that with a frame mount high on the back where the seat used to be, that fuel will feed when the main tank is low. So if I understand correctly, and based on all the discussion, once I open the valve and fuel feeds to the return line, I should see the fuel guage rise?

One additional question, where do I connect/run the vent line from the cell?
Use a pump and be done with it ! Pump transfers are slow But GF is pathetic.LOL GF..
 

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Didi,

I have a 5 gal tour tank I mount behind the passenger seat where the top box goes. This is higher than the main fuel tank. I could not get the fuel to gravity feed into the main. There is simply too much pressure in the return line. I went with the pump because I did not want to drill into the tank.

Pump works great, is cheap, you can stick two of them in and just swap the hoses if one fails. There is plenty of room and the entire install can be hidden.

Here is how mine is installed. This shows it in the top box but I mostly use it with the top box off and the aux tank in a sports bag. Removing the box saves considerable weight when loaded for longer rides. If you click on the Rons letter link it will show you the parts and generally how I did the install.

Hope there is something in there that helps.

http://www.tourtank.com/RonWBMW.html

Best of luck.
 

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Discussion Starter #12
That is one nice, clean installation Ron! The pictures and letter were both very informative. Let me understand something; at some point your fuel level drops to a certain point (in the main tank), at this point you open a valve leading to the aux fuel cell, you then turn on the fuel pump and move fuel from the cell into the main tank via the return line. At what point on the gas gauge before you transfer? Do you stop for this transfer or execute "on the fly"?
 

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MolenaarD said:
Let me understand something; at some point your fuel level drops to a certain point (in the main tank), at this point you open a valve leading to the aux fuel cell, you then turn on the fuel pump and move fuel from the cell into the main tank via the return line. At what point on the gas gauge before you transfer? Do you stop for this transfer or execute "on the fly"?
Didi,

The main tank holds 6.2 (aprox) gals. my fuel reserve light comes on with about 1 gal remaining. As soon as the reserve light comes on I turn on the switch. The switch is wired in series with an electronic solenoid (valve) that opens the line when I turn on the pump. This is done while riding. It takes about 12-15 minutes to pump the 5 gals from the aux to the main thus giving me a nearly full tank again. When the gas gauge stops climbing I know its no longer getting fuel and I shut off the pump.

I added a small LED to my dash that lights when the pump is on because I would forget to turn it off.

You may also want to consider a fuel overflow canister for the aux tank.

If you go this route I can provide you with sources for the parts and so forth. Just drop an email [email protected] and I will share what I have.

Good luck

I just noticed where you are at. Heck, we are neighbors you can just come on by and check it out.
 

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You could also put in a timer relay that shuts the pump off after a set time.
 

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murray said:
Didi
Snip>>__________________
>Can I tap into fuel line with gravity feed system or must I connect to tank?

You are currently plumbed into the low pressure return and that requires a pump

>Should I/can I drill into the existing tank somewhere?

The only metal part of the tank for gravity feed would be where the fuel lines connect, you may not have enough room to drill.

>Should I exchange the gravity feed hardware for the hardware set that includes a pump?

Yes

>I am relying on you all as I have found you to be much more responsive than Terry Smith at Sampson (not to knock Terry, just fact).

Terry is a nice fellow but , you are not the first with issues!

Go with fuel pump and carry a extra pump and switch since these are the only parts that can fail. They will last forever.

Take the time to measure the fuel cell volume, if you are concerned about IBA rides his cells have way more than 5 gallons as advertised. The other bummer is the position of the supply line does not empty the tank and about 12-14 oz remain.
Let me know how much fuel your cell holds and the volume remaining?
Here is my sampson set up.
 

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Discussion Starter #16
Thank you all for great ideas. My plan of attack is coming together nicely. I'll be frame mounting my Sampson cell and moving fuel like Ron does. That way I can even use the plumbing I inherited with the bike. I will be sending you an e-mail Ron for a parts list and directions so I can check out your excellent setup.

A pleasure discussing with you,
 
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