Auxiliary fuel tank

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Dangerous Dave

The older I get, the faster I was...
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Somebody sent me this link from another forum and I kinda like this...especially the smaller one. Kinda stealthy. Looks like a bedroll. They have a larger model too. I might get one of these for my Derbi Tourtank 2.0. It would more than double my current fuel capacity.

Anybody have any experience with these?

 
Not with these specifically, but I did add a 4.8 gallon aux fuel cell recently. Two big questions I'd ask yourself on this:

1) Assuming you're thinking of using it as a gravity system (my recommendation since parts can fail and gravity is pretty constant) What fitting will you use to tap into the existing fuel tank? This was the biggest committment on adding a gravity feed fuel cell to the FJR.

2) Bracketing. You have in your minds eye how and where you'd mount it?

The price seems reasonable for a DIY cell, but I don't get how you think you're going to double the capacity of your bike. The FJR is 6.6 gallons. These kits are 2 or 3.5 gallons respectively.

If you are somehow thinking of more than 4.9--you wouldn't be able to participate in IBA events as there is an 11.5 gallon limit.

All that said, I love my 4.8 custom unit from Bill McAvan of https://www.blm-accessories.com/FuelCells.cfm It wasn't cheap at the $900 price point for all the components, but it IS the cat's ass.

 
If you are somehow thinking of more than 4.9--you wouldn't be able to participate in IBA events as there is an 11.5 gallon limit.
It matters not, as these cells will not pass IBR tech inspection due to venting issues.

Of course, if one never intends to run the IBR with this seup, then it's a moot issue.

 
1) Assuming you're thinking of using it as a gravity system (my recommendation since parts can fail and gravity is pretty constant) What fitting will you use to tap into the existing fuel tank?  This was the biggest committment on adding a gravity feed fuel cell to the FJR.
2) Bracketing.  You have in your minds eye how and where you'd mount it?

The price seems reasonable for a DIY cell, but I don't get how you think you're going to double the capacity of your bike.  The FJR is 6.6 gallons.  These kits are 2 or 3.5 gallons respectively.
Well, it's for my Derbi, not my FJR. The Derbi comes from the factory with a whopping 1.9 gallon fuel cell! Yes on the gravity feed. As far as tapping in, I've got a plan there too. The little Derbi has a really unusual setup. The thing that looks like a fuel tank is actually a pretty damn spacious locking storage compartment. It'll hold my helmet, gloves, full rain gear, and more if you pack it carefully. The fuel cell is a plastic job that runs through the whole tail section and fills from under the rear seat. There happens to be a duct in the tail right near the high point of the tank. It looks like it would be pretty easy to install a quick disconnect tap into the side of the tank right inside that duct. Connecting the auxiliary tank would just require reaching into the duct and snapping on the other end of the quick disconnect on the end of a piece of fuel line coming off the tap on the auxiliary tank. Physical mounting of the aux tank is yet to be seen, but I'm pretty confident I can make it work.

Why all this trouble for a freakin' moped?? I'm glad you asked. :D :D

There's a charity ride in June to benefit pediatric burn victims. This year's event will be the third annual. It's called the Lake Erie Loop. It starts at a campground in Wellington, Ohio. One lap around Lake Erie, across Canada, back to Wellington in one day. You can take any route you like, but you must provide proof that you passed through Detroit and Buffalo en route (like a time stamped gas reciept). It's between 600 & 650 miles for the day. Sounds like a cake walk, eh?

Did I mention that all participants are piloting mopeds, scooters, and small displacement motorcycles 200cc or less?? Ok, 250cc for vintage class. B)

It's a timed event with a cash purse, and 50% of the take goes to the charity. There are classes for 50cc, 125cc, and 200cc with slightly higher limits for vintage machines 30 years old or more. Last year's overall winner did it in 11 hours 34 minutes on a 1980 Honda CB125S. The slowest guys took over 21 hours and there were 2 DNFs.

So, how's that 2 gallon fuel cell sounding now?? :haha:

You can get a better look at the little Derbish on my website at the link in my sig. At a scant 200 lbs fully fueled, it's a hoot to ride, and it has some pretty decent sportbike creds.

There is a "tourist class" for bikes that are too big for the competition categories. You can pay a fee and ride along, but there's no trophy or cash purse for the tourist class. All those entry fees go straight to the charity. Anybody interested can read more at LEL III. Drag out your old step-throughs and Dreams, and show us what you're made of. :assasin:

 
If you are somehow thinking of more than 4.9--you wouldn't be able to participate in IBA events as there is an 11.5 gallon limit.
It matters not, as these cells will not pass IBR tech inspection due to venting issues.

Of course, if one never intends to run the IBR with this seup, then it's a moot issue.
What are the venting requirements for IBA ? I'm guessing that you would need some type of anti-syphon valve.

When I built my tank, I used a simple brass fitting and a double looped rubber hose for venting. I routed it so that if the bike went down on either side, I wouldn't loose much if any gas but it probably wouldn't pass either.

https://www.ldrider.ca/fjrstuff/fuelcell/fuelcell.htm

 
What are the venting requirements for IBA ? I'm guessing that you would need some type of anti-syphon valve.
Critical piece is to vent any spilled gasoline away from the exhaust, heat, or tire. Routing the hose so that it sticks out the back of the bike somewhere usually cuts it.

There isn't an anti-siphon requirement, but many put an extra filter on the vent hose to ensure anything sucked back up that hose isn't particulate matter.

The Utah 1088 requires you catch your overflow. Haven't rigged up a catch rig yet on that, but pondering it.

 
I think that the 2.0 tank looks great! I figure that since I had a plastic red gas tank full of 91octane gas, bouncing around in the bed of my Toyota 4x4 for 174,000miles without fail, its gotta be OK. I dont think that I would modify it anyway. I would just pull over to the side of the road and dump it in the tank, thats all. Max 3-4 minutes. Not bad for nearly 100miles of fun.

@Dangerous Dave - - The Derbi is very cool. How did you get it?

 
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I think that the 2.0 tank looks great!  I figure that since I had a plastic red gas tank full of 91octane gas, bouncing around in the bed of my Toyota 4x4 for 174,000miles without fail, its gotta be OK.  I dont think that I would modify it anyway.  I would just pull over to the side of the road and dump it in the tank, thats all.  Max 3-4 minutes.  Not bad for nearly 100miles of fun.
@Dangerous Dave - - The Derbi is very cool.  How did you get it?
Yeah, it looks pretty darn discreet for a fuel tank. There are some "testimonials" on the website from customers who've crashed on them without any issues. Plastic is tough, so I'm not really worried about that. As for using it just as a holding tank and dumping it in the main tank, I don't think that would work well (not really designed to be "poured" out of), and it kind of defeats the purpose on a long distance timed run, which is to avoid extra stops.

I bought the Derbi on Ebay three years ago, which is about the only place you can actually buy one in the states right now. Derbi, a spanish company dating back to the early 1900s, was aquired last year by italian scooter giant Piaggio (I think they own aprilia now too). Since then, all their assets have been frozen while they're reorganized. As if it wasn't hard enough to get parts before the takeover! They don't enjoy nearly the popularity here in the 'bigger is better' U S of A that they do in other countries. A pity, since they build some really cool stuff. Those lucky brits can actually get a 125cc version. The rear view bears a striking (not by accident I'm sure) resemblance to a Ducati 916/996/748/etc. It's kinda like owning an old Triumph...it's finicky and hard to get parts for, but I love it anyway. I confess to having a real soft spot for small displacement two-strokes. I've owned several, including an RD350, RZ350, RD400, YSR50, and the Derbi GPR50R, which has been bored and stroked to a 75.

650 miles on an FJR in a day isn't really a problem. It's a whole different story on a bike that has to draft minivans to keep up a decent highway pace. Not that there's really a comparison, but it's kinda like a "mini Iron Butt". Again, no offense to the real Iron Butt guys, but hopefully you see my point. Reliability (and sanity) comes into question when flogging a 75cc 2-smoke wide open for a whole day. A mechanical failure on the other side of the lake would suck for sure. Fortunately, I've got a buddy in Ontario from the VTX forum who I believe would come to my rescue if things went awry. I'll have GPS, Ipod, food, drink, and some emergency items with me. That extra 2 gallons of fuel would sure be a BIG help in saving on stop time. I'm pretty jazzed about the whole thing. I know it sounds crazy, but that's the story of my life...half fearless, half brainless. :D :D :D

 
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