Fuel cell to use or not to use. Is the question.

#1
I found a few aluminum fuel tanks online under 80 bucks. 5 gallon, sender, vents, outlet ports in -10. 12"x12"x 8". With a 2" sump. Foam filled baffles. Thinking of mounting over passenger seat on my FJR1300 with brackets . Mount a fuel gauge on dash and fuel hose gravity feed the system . Are these race cells good to use .
 

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Greg Rice

Premier Member
IBR Finisher
#2
I found a few aluminum fuel tanks online under 80 bucks. 5 gallon, sender, vents, outlet ports in -10. 12"x12"x 8". With a 2" sump. Foam filled baffles. Thinking of mounting over passenger seat on my FJR1300 with brackets . Mount a fuel gauge on dash and fuel hose gravity feed the system . Are these race cells good to use .
Yes, that makes a good aux tank. How are you planning to tap into the main tank on the FJR? I have been testing for 30,000 miles the BMW method which is to use the main tank vent line and the fuel pump pulls the gas from the aux tank. I have some information on my website on how I did it. If you are interested in using the method I am using let me know and we can talk.

http://www.gregrice.com/bike/fjr.html
 
#3
Great info Greg. So the pic of the tank vent tube goes to the top of the tank. How does the fuel enter from the bottom of tank to fill the main tank if the tube ends up at the fuel cap.
 

EricV

Premier Member
IBR Finisher
#4
Those tanks are fine for fuel cell use. Keep in mind that the cell is higher than the main tank on the FJR, so you don't really need a gauge for the fuel cell. When they are tied together, either as a traditional aux tank with a bulkhead fitting in the main tank, (the preferred and proper method), or via the sketchy vent line siphon that leaves you w/o a vent for the main tank, the only gauge you need is on the main tank.

Yes, I'm biased. I've run a bulkhead fitting method on my FJR for 120k+ and dealt with the problems from the vent line siphon method on other bikes. I consider it a Bad Idea™ to not have a vent for the main tank, except thru the aux tank on the FJR. 30k miles for Greg is about 4 months. ;)

@Greg Rice - Have you done a rally with that set up yet?
 
#5
Thank you Eric for another great tip. Bulkhead sounds like the best choice . But concerning about drilling and future leaks. Another is actually drill and weld a new bung the paint.
Just worried about aux tank being higher when full as not to overfill the main lower tank. But I guess that avoided by running the main empty the opening up aux when needed.
 

Greg Rice

Premier Member
IBR Finisher
#6
Those tanks are fine for fuel cell use. Keep in mind that the cell is higher than the main tank on the FJR, so you don't really need a gauge for the fuel cell. When they are tied together, either as a traditional aux tank with a bulkhead fitting in the main tank, (the preferred and proper method), or via the sketchy vent line siphon that leaves you w/o a vent for the main tank, the only gauge you need is on the main tank.

Yes, I'm biased. I've run a bulkhead fitting method on my FJR for 120k+ and dealt with the problems from the vent line siphon method on other bikes. I consider it a Bad Idea™ to not have a vent for the main tank, except thru the aux tank on the FJR. 30k miles for Greg is about 4 months. ;)

@Greg Rice - Have you done a rally with that set up yet?
Hi Eric, I have not ridden any rallies yet but I have completed 7 BBG’s with a couple of them back to back.

I have ridden two 1700+ mile days also and so far no issues.
 

EricV

Premier Member
IBR Finisher
#7
@MtyQuinn - Drilling is EASY. (I believe the location is different than this Gen I write up on newer models) Use Stat-O-Seals on both sides of the tank and it won't leak, ever. You can get these in various sizes from many sources. Hydraulic hose shops often keep them in stock or you can buy them online. Pegasas is one online source. A good thread sealing compound is also a good idea. I like Loctite 567 thread sealant for fuel fittings like the bulkhead fitting. Note that it needs a lack of oxygen to cure, so any excess outside the threads will not cure and is easy to clean up. It's fuel proof as well. I've installed three different bulkhead fittings with this and Stat-O-Seals with somewhere around 350k miles of use w/o any trace of leak or weeping. I am a retired machinist that worked in the hydraulic tools division of Stanley Works. I used lots of different thread sealing, locking, retaining, filling compounds, including near daily use of 567 and know it's properties well.

Some important things to know with any fuel cell project - Keep the fuel line from the aux to the main tank as low and strait as possible. Try not to go up and over an obstruction. I drilled some holes in the plastic under seat tray to allow a straiter run, for example. Do install an inline fuel filter off the aux tank. A clear plastic disposable one, not a glass one. Vibration can cause the glass ones to come apart and leak. The clear plastic filters allow an easy visual check of both fuel flow and debris in gas, which can provide a clue or even an early warning if you get contaminates in your fuel.

@Greg Rice - Please report back when you go places for bonus points, under conditions that you didn't choose, especially in the West where distances are more vast and a rally bonus can take you far off the beaten path. Burning up the interstate is a good proof of concept in fuel flow, but lacks the variables rally conditions can cause. And I do also wonder if you've ridden in extreme heat with that set up yet. That's a common condition for vent line aux cell issues.

Every single person using the vent line method can tell you stories about having no access to aux fuel and being unable to fix it during the ride. (Ask the Lehmans about their IBR and the Africa Twin aux fuel issues.) Your turn will come, if it hasn't already. On the FJR if you have no vent line for the main tank and have issues with your vent line aux set up, you run the risk of several negative problems, the least of which is starving the bike and having it stop running. There have been imploded tanks in the worst case scenario I can think of with vent line problems. The more common issue is a vacuum in the tank that doesn't allow the gas cap to open or just no fuel feeding from the aux tank. On a bulkhead system you can deal with it, should a problem arise. Usually quickly.

At the end of the day it's a personal decision driven by several factors. Choose what works best for you.
 
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EricV

Premier Member
IBR Finisher
#9
Great words. Thank you guys for the tips . I will go with bulkhead fitment. So I will move forward with the fuel.
Another tip, make sure you have dry break fittings under the seat that you can access, and place the fitting junction far enough to the rear of the bike that when you separate them you can still raise the tank w/o completely removing the fitting and line. It makes service a lot simplier.
 

EricV

Premier Member
IBR Finisher
#11
Dry break . Got it. Do you any pics of your fjr tank bulkhead .
That was about 16 years ago. Here are some pics of my Super Tenere, which was similar. The tank is up in these pics, which pulls the hose forward. Typically I would need to un-do the dry break fittings to get the slack to lift the tank. Because the dry break fittings are under the seat, access is quick and easy. The filter location right off the cell makes if viewable while the seat is on. I did the same thing on the FJR with a different style filter.



Marine 5/16" I.D. fuel line with marine dry break fittings, (Chrysler Force style). vvvvvv

Valve and filter vvvvvv


edit - I like to use marine fittings because they are reasonably priced and AVAILABLE. I always carried a spare set, but you can get them at any Marine dealer or NAPA store. Seasense is a good brand and I've personally used these for many tens of thousands of miles. Male / Female The 3/8 hose barb can be used on 5/16" I.D. hose and gives good flow. 1/4" hose flows slooowly. 3/8" I.D. is noticeably harder to route in the tight confines of the under the seat/tank world on the FJR. The marine grade grey hose is double wall of sorts and more resistant to damage. It's made to sit in the bottom of open boats with outboard motors and tanks sitting in the bottom of the boat. The expectation that it will be stepped on, etc is there, so it's tough. Regular 5/16" fuel line works too, I just like over kill.
 
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EricV

Premier Member
IBR Finisher
#13
I like overkill as well. I am very particular to custom mods aswell. So I like and will use your techniques.
When you find a fuel filter that you like and meets your needs, buy 3. Keep one on the bike for an emergency spare and the other in the garage with info on where you bought it so you can get more years later.
 
#14
Good advice Eric. I'm on a mission now. Whats frustrating now is finding an affordable tank that ships to California. So many laws and regulations and cancer causing things. Most tanks can't ship to my state. So the shopping continues. I found a good used on in Washington state. Just go that route.
 

Stephen!

Premier Member
IBA Member
#15
Good advice Eric. I'm on a mission now. Whats frustrating now is finding an affordable tank that ships to California. So many laws and regulations and cancer causing things. Most tanks can't ship to my state. So the shopping continues. I found a good used on in Washington state. Just go that route.
Got any friends in Nevada or Oregon?