Auxiliary Tank

[MAXIMAN]

Some of you may have seen the aux tank I rigged up for the ride to Reno using a ABS marine grade fuel tank for an outboard motor. I strapped it to my luggage rack and it gave me an extra 3.5 gallons. It rocked for the added distance. The thing I didn't like is it ate my rack space.

Well I was so pleased with the system I decided to build a tank that would allow me to still use my rack to place bag on. I welded up an aluminum tank that will sit on my luggage rack just like the outboard rig. But this one will allow me to sit a bag on top of the tank. This aluminum tank holds 2.8 gallons and should give me an extra 90 to 100 miles of range beyond the normal 150 or so of the Maxim. Here a few pics if you're interested. It has an 1.5" inlet and a 1/4" outlet/drain.

The filler is the rear of the tank


left side


right side


vented cap

[mro]

Auxiliary Tank

Very good welding. My 80G will now go just over 100 miles before going to reserve, real nice to have a little back-up.

My mig sucks at aluminum. Also like your shop , lota space. Mine jammed w/misc. equip. and usually have to move one thing to work on another. When I can get a good enough excuse I'll get a tig, so I can do aluminum too.





mro

[John]

Here's a thought...

Damn, thinking hurts ...How about fabbing up a tank that will sit under the luggage rack? Angle the bottom towards the rear, following the contour of the fender, and place the petcock at the rear of the tank. As long as the bottom of the tank is above the top of the carbs, then gravity feed will work. In fact you could drain the spare tank before switching to the stock tank, and that way you still have the gauge/light to warn you of a low fuel situation. I have the same problem with being short winded on long rides. Now, I have attached a 3'x3' piece of plywood to my rack to carry a large cooler, a tent and sleeping bag, and such. That worked fine for those light weight items and didn't place too much weight behind the axle. Your spare tank looks good. Maybe you could get real fancy and include a sight glass or a float gauge.

[TopCatGr58]

Another idea?

Hey John and Max,

How about fabbing up a tank bag type design, so instead of using a tank bag for cloths and such, mount rubber cushions, and straps that would attach it to the existing tank, and then you've got the height to gravity feed it to a "Y" in the fuel lines, and drain it first, then rely on the main tank as you stated for the reserve gauging and function!?
OUCH, that hurt my brain, too!
T.C.

[MAXIMAN]

Re: Auxiliary Tank

Originally posted by mro
Very good welding.

mro

Yeah...I'm real good at welding aluminum. Especially when I hire it done.

I've got a stick welder and a mig...but no tig. So I had to hire it done. Regarding the shop: the reason it's so "roomy" is I've threatened everyone in this outfit with Chinese water torture if they try to turn my shop into a "storage room".

[John]

Good idea, but...

That woud look kinda ugly, don'cha think? Granted, it would be very practical. The tank is an integeral part of a bike's appearance, and to upset those lines with an ugly bag thing on top of it would be herasy. Hell, my ugly ass on it is enough of a distraction... At least with the tank mounted to the rear, the eye is not drawn to it, and it won't distract from the look of the bike in general, and should there ever be a spill/ leak, it would not be as dangerous as it would be if it was mounted on top of the fuel tank.

[MAXIMAN]

Re: Here's a thought...

Originally posted by John
Damn, thinking hurts ...How about fabbing up a tank that will sit under the luggage rack? Angle the bottom towards the rear, following the contour of the fender, and place the petcock at the rear of the tank. As long as the bottom of the tank is above the top of the carbs, then gravity feed will work.

"Oh Lord I done done it! oh Lord I done it! Oh lord I done done it! Done done whatcha told me to do!" (old church revival song)

The problem was the entire capacity of the tank wouldn't drain into the main tank. The aux tank sits lower than the main when under the rack. I would've really had to rig up some freaky octopus to have the aux supply the carbs directly and bypass the main. OR I could install an electric fuel pump to pump the fuel over into the main. Too much hassle for me.

This rig is much more simple. I simple flip the right main petcock to prime and open the aux petcock. Then fuel flows from the aux to the main via gravity.

And since I only use it on long raod trips it's not even mounted to the bike most times...Hwether it's under the rack or not is a non-issue with me.

[MAXIMAN]

Re: Another idea?

Originally posted by TopCatGr58
Hey John and Max,

then you've got the height to gravity feed it to a "Y" in the fuel lines, and drain it first, then rely on the main tank as you stated for the reserve gauging and function!?
T.C.

This rig already works that way. The luggage rack is higher than the tank (at least on my Maxim) while riding. Once the reserve warning / fuel light comes on I just switch the right petcok to prime. And open the aux petcock. Fuel drains from the aux into the main essentially like "In flight re-fueling" .

I have just one "Y" connection that merges the aux fuel ine into the main tank/carb line.

I used this setup on my ride last September to the Reno Rally. It worked flawlessly. Except then I was using a outboard motor tank. I think I've posted some photos around here that show it.

[John]

The temporary mount is a good idea. I ride to work as often as I can, but I need to gas up after 2 1/2 trips to work and back. I hit the road at 5:15 am, and that's cutting it kinda close, so I don't usually have the time to get gas then, and I like to get home before SWMBO leaves to teach after school classes (3pm), so that leaves out gassing up on my way home from work, and some days I have to pick up our son after school, so I don't have much time to dauddle around after I get off work. If I had an aux or larger tank, then I could get a whole weeks riding in one fill up.
I can't even make it to Turner Falls/Davis without having to gas up in southern OK, about 30 miles from Turner Falls. It's 120 miles from my house to there. If I stop at the same gas station on my way home, as I do on the way up there, then I can make it all the way before needing fuel again.

[MAXIMAN]

Another thing I keep forgetting is you guys are riding specials...(most of you).

Since the Maxim has an LCD display fuel gauge I can see how much fuel I have. And believe it or not the Maxim's gauge is pretty darned accurate.

It indicates with 4 bars. When the last bar starts "blinking" the fuel warning comes one.

At that point I have about 7 tenths of a gallon in the tank and can go an additional 20 to 25 miles.

It's convenient to switch the aux to drain into the main. That way I can watch the fuel gauge bars light back up one by one and be more up to date on my fuel situation.

Since the Specials don't employee a fuel gauge then that would be a non-issue wiht you guys.

[MAXIMAN]

John

Personally I love the way the Specials look. They are my fav! But that tiny little tank is a PITA.

I have heard a standard tank will fit a Special...true?

Of course that would defeat the whole "look" of the Special. But boy wouldn't one of those Venturer 6 gallon job be da bomb?

Another reason I like the Maxim. it has the sexy curvy tank but hold 5.1 gallons. All my riding buddies that mount Specials are looking for fuel between 90 and 100 miles usually. Zilla can go 150 on the stock tank pretty consistently.

[BLUEJEEPLAB]

I guess the 108 (nearly consistently) I get before the "Walk" light on Battle Cruiser is pretty good. It isn't so bad, that's about the time my butt is telling me that I need to walk around anyhow. It really would be nice to have the shape of the Special tank and an extra gallon or two.

[xs650mike]

"Bedroll Tank"

There is an outfit making an aux. tank that looks like a bedroll which can be mounted either on the bars or on a luggage rack. The thing just gravity feeds into your gas tank as the fuel goes down. I'll try to find a link to the company website as soon as I remember what it's called. Here's a pic of the tank on an XS650H chopper:


The fuel light on my XS11SF lights up at about 124 miles in normal riding and I have to switch to reserve about 8 miles later. In 80 mph Interstate travel it lights at about 112 miles. The bike is completely stock.

[prometheus578]

"Tanks a lot"

I like that "bed roll" idea. ...beats putting a plastic gas can in my saddle bag.

[SG-Olli]

Bedroll?

Hmmm...
as long as you're riding straight on the highway that might work OK. But while going twisties I would not like the additional weight on the steering.
But what do I have to complain with a 6 gallon standart tank.