Tag-Along Aux Fuel Tank (joe2lmaker)

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Excellent Joe!

IIRC you set this up with a fuel pump (?)...got an pix of that?

I'm assuming this plumbing arrangement is for the prototypes? The production tanks have the fuel outlet about where your QD is, right?

 
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OK, the pressurized tank proof-of-concept solution. One two-way valve. Position 1 vents as normal. Position 2 closes vent path, opens path to pressurizer bulb (from a blood pressure cuff). The bulb provides more than enough pressure (inches of water, no problem of stressing the tank) that pushes fuel from TAT to main tank. It works really, really well.

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Now for the next to final install.. I want to buy a valve with npt threads in order to reduce valve height. I found a shorter nipples, shown below. As is, it clears the Givi back rest, but want a cleaner look. Additionally, after I get a Lynda or other cover, the bulb will be inside a pocket.

Oh, the overall reason for pressurizing the tank is to A) quickly displace fuel from TAT to main, B) more importantly, when both main and TAT are close to reserve levels, I want to move all TAT fuel up front. That way I KNOW exactly how many miles I have left. Otherwise, knowing me, I'd think 'WTFO, I *should* have some left in the TAT, it will be OK." But since I've not found a low pressure pop-off check valve, if running uphill, you can actually drain the main back to the TAT. This way, fuel levels are a known constant, not a variable. And for a CandyButt Association Rider like me, that's very important you know. :p

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Relocated the bulb so I can access it when riding..

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Added a back rest - here's the views. The back rest needs be cut down by at least 50% to provide seat room, but the concept works. Currently, I'm using Velcro. After determining the correct thickness, I'll fab and weld an adjustable rail to the tank so I can raise and lower it, and hopefully even have the pad articulate vertical position.

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BTW - I hit a MAJOR pot hole last Saturday while on a goat trail - lost focus, was watching a huge RedTail hawk with dinner in the claws.. Nailed that pothole square, rear tire off the ground, magnetic tank bag flying loose, feet off the pegs kind of ride - and TAT did just fine. Thankfully, so did the front rim.

 
Pretty interesting Don. ....and I suppose that bulb could also be used to air-up those inflatable farm animals .....ya know, the CBA mascots, the ones you bring on those loong rides.

BTW: has any part of your anatomy expressed jealousy since you're now squeezing the bulb instead? Because if so, you cold likely make your boy-toy happy again by replacing that bulb with a small compressed air bottle and simple little valve. Just a quick hit from the compressed air would do the same thing. put a valve in it, - top it off with compressed air every time you air up your tires ...and I'm sure that would be plenty often enough. No doubt with even a small canister could last at least a half dozen tankfulls.

you're welcome in reno ....John

 
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... pressurizer bulb (from a blood pressure cuff)...
Just a thought, could the "rubber" of the bulb be affected by fumes from your petrol (sorry, gas)?
Well, I don't know. My hope is that fuel would never reach the bulb - the TAT would be close to empty prior to 'energizing' the bulb.. I guess time will tell. I 'purged' the TAT again tonight on the way, in flight, and it worked great.!

 
... pressurizer bulb (from a blood pressure cuff)...
Just a thought, could the "rubber" of the bulb be affected by fumes from your petrol (sorry, gas)?
Just a thought...a priming bulb from an outboard boat motor tank might address the potential rubber deterioration issue and still work well pumping up the fuel cell.

--G

 
... pressurizer bulb (from a blood pressure cuff)...
Just a thought, could the "rubber" of the bulb be affected by fumes from your petrol (sorry, gas)?
Just a thought...a priming bulb from an outboard boat motor tank might address the potential rubber deterioration issue and still work well pumping up the fuel cell.

--G
Since my bulb is only pushing air, not fuel, I don't think it will matter any - it would be a stretch situation for gas to make into or around the bulb. I'm simply pressurizing the area above the gas.

 
... pressurizer bulb (from a blood pressure cuff)...
Just a thought, could the "rubber" of the bulb be affected by fumes from your petrol (sorry, gas)?
Well, I don't know. My hope is that fuel would never reach the bulb - the TAT would be close to empty prior to 'energizing' the bulb.. I guess time will tell. I 'purged' the TAT again tonight on the way, in flight, and it worked great.!
I thought the fumes would get into the bulb, and that might be enough to affect "sensitive" material. Hopefully you won't have a problem.

 
... pressurizer bulb (from a blood pressure cuff)...
Just a thought, could the "rubber" of the bulb be affected by fumes from your petrol (sorry, gas)?
Well, I don't know. My hope is that fuel would never reach the bulb - the TAT would be close to empty prior to 'energizing' the bulb.. I guess time will tell. I 'purged' the TAT again tonight on the way, in flight, and it worked great.!
I thought the fumes would get into the bulb, and that might be enough to affect "sensitive" material. Hopefully you won't have a problem.
Well, I've run dozens of tanks of fuel through now, no problems with the little squeeze bulb. I know time will tell, but I gotta say I really like being able to fully empty the TAT quickly, then rely entirely on the gas gauge for remaining fuel / miles.

 
Hard for me to believe it's been nearly a freaking year since installing this tank.

One year later, and it still doesn't have a cover - I can't imagine not having the tank on long enough to make a cover!

The rubber squeeze bulb is still alive, and no leaks from the bulk head fitting in the main tank or from the aux tank either. (knock on wood)

Thanks again Joe!

 
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