Auxiliary Fuel Tank

#1
I've been reading around here for the majority of the day and at this point I am in need of some guidance.

Correct me if I am wrong but the gist I got is there is 2 ways of adding an auxiliary fuel tank.

1. Drill into the tank and make an additional pep cock to run a hose to the main tank from the auxiliary.

2. Add a T connector to the vent hose and gravity feed?

-the height between the aux space and the main tank is significant enough that unless i need to get up to injector pressure, gravity feed will be sufficient.

If anyone could help point me in the right direction or provide the information needed to get this completed. I'd really like to have a larger range instead of resorting to a Jerry can, I have a few days longer than a month and I've tried to approach this problem before and given up.

I'm planning to get started in Iron Butt this summer with a trip from Northern WA to Southern CA. I currently have a 2005 GSX-R 600 with lets just say minimal fuel capacity. (I know, get a more suited bike for the ride.... However I enjoy the thrill of doing things outside the norm.)

Main tank (4.5gal tank)
Auxillary tank (3-5 gallon tank) (rear seat mounted 14" x 14" area)
 

DrNeo

Premier Member
#2
Beebowbow -

You're correct.The third option is to "T" into the fuel rail return line. If "T-ing" isn't an option, most people drill a plastic tank, but I assume your tank on the GSX-R is either steel or aluminum?

I'd be curious about what MPG you're currently getting... most would be hard pressed to stay in a sport bike tuck for more than 150/200 miles at a time. A decent gas stop should take you no more than 10 minutes tops. (A lot of top-level riders are in/out in under 8).

Even at a speed limit of 65mph, you still have ~8.5 hours of "off-bike" time in a standard SS1000.
 
#3
Tank: Steel

Based on some further research and process of elimination that no other method will work, I'm going to be popping a hole in the tank.
(ordered a bulkhead with some O'rings and some permatex gasket to get a solid seal)

MPG :
6th gear with a tail wind - 40mpg
Typically 30-34mpg though.

No fuel gauge only a warning light at ~.75gal reserve which comes on around 100miles.

I can get fueled up at a gas station in no more than 5 minutes in my current stock state. However I'd rather dictate my stops on when i would like to stop as opposed to being forced to stop at a gas station for every rest stop and then a gas station per ~80miles just to be on the safe side. At the end of the day my #1 priority is not SS1000, I'm just looking to have fun touring on a not-your-typical-tourer and I don't want the only sights i see to be different gas stations. I'm riding from WA > SoCal without any time restrictions and then on my way back SoCal > WA i plan to attempt SS1000.
 

thekaz

Premier Member
IBR Finisher
#4
Tank: Steel

Based on some further research and process of elimination that no other method will work, I'm going to be popping a hole in the tank.
(ordered a bulkhead with some O'rings and some permatex gasket to get a solid seal)

MPG :
6th gear with a tail wind - 40mpg
Typically 30-34mpg though.

No fuel gauge only a warning light at ~.75gal reserve which comes on around 100miles.

I can get fueled up at a gas station in no more than 5 minutes in my current stock state. However I'd rather dictate my stops on when i would like to stop as opposed to being forced to stop at a gas station for every rest stop and then a gas station per ~80miles just to be on the safe side. At the end of the day my #1 priority is not SS1000, I'm just looking to have fun touring on a not-your-typical-tourer and I don't want the only sights i see to be different gas stations. I'm riding from WA > SoCal without any time restrictions and then on my way back SoCal > WA i plan to attempt SS1000.
If you check out the model of bikes that have finished the IBRs I think you will be surprised ;)
I have done most of my IBA rides on a ZX12R which has a range of near zero LOL
Drilling a tank and adding a fitting is more work but is the best way IMO
 

OX-34

Premier Member
IBR Finisher
#5
beebowbow,

I've drilled the tank and fitted a bulkhead fitting on a half a dozen steel bike tanks and that way works just fine. Add an aux with some form of inline tap and you're ready for miles and miles of smiles.

There is another way. In your first post you mentioned the option of 'T'ing into the vent line. That does work but it may require a few fiddly fuel lines. You don't have to 'T' into the vent. Just take the vent line off the Suzuki tank and attach the outlet fuel line from your aux tank. No tap required. The Gixxer tank can be loosened and tilted back to stand just about upright to reach the vent line (next to the overflow line). The bike tank now vents via the aux tank vent.

When both tanks are full and you ride away from the gas station the fuel is pumped out of the bike tank by the fuel pump. That sucks fuel from the aux straight into the bike tank litre for litre. At the same time air is drawn (litre for litre) into the aux vent line from outside. Once the aux is empty the bike tank starts drawing in air straight through the aux.

The filling procedure is strict. Starting with the aux empty (it was empty in your shed) first fill the bike tank and put the cap on. Fill the aux and put the cap on.

Do not open the bike tank unless you are positive the aux is empty - otherwise fuel will pour out the moment you open the cap.

Do not fill the aux unless you are positive the bike tank is full. Otherwise you may create a vapour lock as there is a big bubble of air at the top of the bike tank.

That air can't get out and the aux fuel can't easily get in. If the bike seems to be starved of fuel out on the road when you know you have gallons on board this is the likely cause. Carefully open the bike cap and you will hear air hissing. Wait a bit and the fuel from the aux will start to flow and fill the bike tank to the top. Cap it before it overflows.

Mounting on a sports bike can be easy. Buy a spare pillion seat from eBay or a wreckers. Drill straight though it and bolt appropriately. Add some 'no tools' brackets to access the pillion grab rail mounts/bolts or just use some strong cam buckle straps to hold the tank rigidly. Removing the tank to take it back to canyon carving mode is then quick and easy with the key plus those simple mounts. Put your oem pillion seat back on. Leave the aux outlet line as your vent if you are regularly going to do LD rides on the Gixxer, otherwise just lift and tilt the bike tank and swap the aux and vent line back again.


This only a Givi box, but it will be something like this.

 

cacomly

Premier Member
IBR Finisher
#6
On my 2007 Sportster I had a bung welded into the bottom of my tank since there was no easy way to get to the back of a bulkhead fitting.
 
#7
Two bits of advice from my actual experience: If you drill into a steel tank for the fuel line addition, once you have the proper location, use JB Weld to completely seal the tap. Rubber oil rings can and will leak. Also, don't fill the tanks and leave the bike sitting in the hot sun or you may see fuel pouring out of the vents. DAMHIK.
 

ibafran

Active Member
#8
There are many ways to skin this cat. Here is another and is the way that I plumbed into an 05 Tri. Sprint ST plastic tank. Some tanks have an access plate that mounts the fuel pump, fuel gauge sender, various return lines. The access plate is cheap compared to the tank. Thus, one can screw up a plate and buy a replacement(s). Often there is room on the plate for a bung. As carefully as possible, decide if there is room on the plate for a bung AND room for the bung on the bike so that the bung does not hit a frame rail or some other bike part. My app required an immediate right angle turn.

My aluminum aux tank came from Summit Racing and was rated as 'race' ready. Considering how easily it failed in the rigors of the Far North, my next tank will probably be a Poly.

I used ordinary, hardware store grade, brass pipe fittings with tapered pipe threads. 1/8th pipe is adequate for the job but has a slow flow. 3/16th is better. 1/4 inch is great. 5/16 is probably about as big as any bike has room for. I drilled and taped my plate for pipe thread and screwed my fitting in direct. I sealed my threads with blue Leak-Loc, a refrigerant sealant that does not dry out and is easy to clean up. when I installed my fuel hose on this fitting with a worm gear hose clamp, I safety wired the clamp and I safety wired the fitting so that it would not back out and leak due to bike vibration.

Route the hose back from the tank to a place where it is easy to install and operate the "self sealing" quick disconnect (QD). Install and remove the empty tank once or twice to prove to yourself that you can indeed get the tank off the bike for service without the aux fuel line giving trouble. Once you are satisfied that the hardware positioning is good, lay the tank in position w/o securing it and flood the access plate with fuel to check for leaks. If it leaks fix it till it doesn't. Bolt tank in place. Secure aux hose with sacrificial zip-ties. The bike's tank is now plumbed for aux fuel.

The QD that stays with the bike needs to be protected when the aux fuel tank line is not connected to it. Dirt and crudola should not be allowed to build up in it. I used a matching QD part and a bit of plugged hose to preserve the fitting on the tank. Because this fuel line might have to be fished out of the bike when the tank is removed for service, it is not a good idea to have the shut-off valve and fuel filter as part of this assembly. The fuel filter and shut off valve might best get removed with the aux tank when the tank is not on the bike.

Stuff I learned the hard way: Some aux tanks have a check ball in the vent which can get stuck and not allow the tank to vent causing a vacuum lock. Tapping on the check ball vent tube will loosen the ball and fuel will flow like it should. Some riders remove the check ball to prevent this. Once I knew about this, I didn't mind the occasional tap.
Some aux tanks have aluminum mounting tabs. These tabs are fine for ordinary street riding. They will not stand the stress of sustained rough riding and may not stand the strain of one or two real good slams. Daily inspection of these tabs for stress cracks is highly recommended. Using some sort of anti-vibration material with them is a good idea. If the tank is mounted on a large flat plate, a sheet of anti-vibration material under the whole of the tank could be a good idea. IF...the bike is to be ridden in rough conditions in the Far North like the Haul Road or across Siberia, the tabs will be a total fail. Make at least 2 hold-down brackets to fit over the tank to keep it from moving in any direction. Adding ratchet strap anchors for straps going both ways and using straps in addition to the hard brackets is not over-kill. The mounting plate or whatever is being used to hold the tank to the bike should be stout enough to suspend the whole of the bike.
Placing the aux tank over the pillion is probably best if there is a lot of weight. I put 30lbs (3.25Gal + tank) on a rack over the tail piece because the pillion was loaded with 75lbs of gear. The rack/tank survived the street for several years. Neither survived the Haul Road/Campbell/Dalton combo ride.

I really enjoyed having plumbed aux fuel. Currently, I have no real need for it and have not replaced the system that failed. I did take another long trip in the Far North toting extra fuel in a 4gal Roto-Pax. The Roto-Pax was laid across the pillion and gear packed on top of it. It was sufficient to my needs at the time.

your fun may vary,
fran
 

IBA ZX-9R

Active Member
#10
I seemed to remember a friend who road with me on his GSXR-600, he was getting a little over 200 miles to the tank off 4.5g. His bike was in stock form, gearing, fueling, etc. 200 miles to the tank is respectable for IBA riding and touring, but if you really are serious, you'll want something that puts you closer towards 300.

Let us know how the new tank(s) work out for you. I really appreciate what you're doing with your 600 sportbike. Not many of us who like to ride all day, types.
 

Marc11

Premier Member
#11
I seemed to remember a friend who road with me on his GSXR-600, he was getting a little over 200 miles to the tank off 4.5g. His bike was in stock form, gearing, fueling, etc. 200 miles to the tank is respectable for IBA riding and touring, but if you really are serious, you'll want something that puts you closer towards 300.

Let us know how the new tank(s) work out for you. I really appreciate what you're doing with your 600 sportbike. Not many of us who like to ride all day, types.
The only issue with a 200 mile range is reserve. How much is left, often if you have a 200-225 max range you're looking for fuel around 180 miles, that's looking for fuel every 2 and a half hours or so and a stop every 3 hours or so, over the course of a long multiple day rally or ride, let's say of 2500 miles, you are stopping twice as often when compared to a bike with a 400 mile range and you stop every 350 miles.

When I was running with only a 250 mile range I was looking for fuel every 200 miles and often had to stop even sooner depending on where I was with fuel and when the next potential fuel stop was. And I can say it felt like I was always looking for gas...always, and I can assure you on the back roads heading to Yellowstone or back roads heading to a place litterally in the middle of nowhere at 3 am you are always worried about fuel, so much so you end up stopping at every fuel stop since you don't know when the next will come up, some towns had one fuel pumps and often they weren't open 24*7.

If you assume a very effecient 10 mins per stop, those extra 7 stops adds over an hour to your travel time.

Then there is the margin factor, it's nice to know if you are some place at o dark thirty and hit the 300 mile marker, you have another 100-150 mile range in your tanks if needed....and trust me, I've been places where it really was needed.

So, of course 180-200 miles is perfectly fine and perfectly manageable, no one NEEDS 350-450 mile range, but man it sure is nice having it.

Heck even for my daily commute it's the difference in getting fuel once to twice per week vs one every two weeks.
 

Clive Rand

Premier Member
#14
I like the idea of a fuel cell on the bike as well as main tank, I have had a look over my bike, and I know it is not like the sport types but I am considering using what I believe is a balance pipe at the front of my tank, I am a bit paranoid about leaks, if this idea works I am not drilling anything, just putting a tee piece in under the tank, from there using a one way valve then running a fuel line under the tank to the rear of the bike. I thought of using a fuel solenoid under the seat and a fuel line up to the rear of the bike into a tap, from here there will be a place to connect the aux tank, using a low pressure electric fuel pump attatched to the aux fuel cell to refill the main tank on the move. I have a fuel guage on the bikes main tank, and I am thinking of installing a fuel guage to the fuel cell as well so I know how much is in either tank. how many think this is a bit over the top, and how would you change it.
 

Marc11

Premier Member
#15
I wouldn't worry about a fuel gauge on the aux tank. As for the balance pipe as a tie in point, could work as long as it's not a high pressure return line which may complicate things. You also may not need a fuel pump if your tap is lower than the cell.

I'd also have a quick disconnect to remove and isolate the tanks if needed.

IMHO. The simpler the install the better. Less failure points and easy to isolate if something goes wrong.
 

Clive Rand

Premier Member
#16
I wouldn't worry about a fuel gauge on the aux tank. As for the balance pipe as a tie in point, could work as long as it's not a high pressure return line which may complicate things. You also may not need a fuel pump if your tap is lower than the cell.

I'd also have a quick disconnect to remove and isolate the tanks if needed.

IMHO. The simpler the install the better. Less failure points and easy to isolate if something goes wrong.
Thank you for the quick reply, I may have a wrong name for the pipe in question, it is a small pipe connecting the left to the right side of the tank right up front at the bottom and goes under the frame and not connected to anything else, kind of why I am thinking of using it, I had thought of using a boat fuel tank connector/coupler, some of the names I use may be different to some of you as I am in Australia, and we have our own way of bastardising the English language. Hehehe you wouldn't want to hear the Australian version.
 

Marc11

Premier Member
#17
Ah I see you have two tanks. Then a brass tee fitting should work perfectly. The only worry I'd have is if your aux cell capacity is greater than any one of your tanks you'd risk filling and over flowing one of the tanks. I'm thinking if the fuel from the aux tank flows in faster than the tanks can balance out normally.

Make sense?

I had to work on a certification with your government several years ago for a few months for my company after that exercise I speak perfect Aussie and can say with confidence our government backwards rules and regs has nothing on yours!
 

Clive Rand

Premier Member
#18
No Marc, I have only one tank, mine is a 2013 model, I am assuming it has a pickup on one side and because the tank straddles the frame, there is a short pipe from the left side to the right side, which is why I considered it to be a balance pipe, to as I see it, balance the 2 parts to maintain an even level on both sides.
 

Marc11

Premier Member
#19
I see. I've never seen that before, I've owned some pretty old bikes with a frame backbone that split the tank and none have had such a pipe.

The closest over seen was an aftermarket 10 gallon tank I had on my klr, that had a little vac pump to move fuel from the right side to the left where the fuel petcock was to ensure all the fuel was available and used. I'm guessing the purpose of your pipe is similar but simpler.

Still if it is really just a pipe to balance the fuel level between the two halves it I would think your idea would work, still wondering if the fuel would flow into the two halves or would it run into issues.
 

Clive Rand

Premier Member
#20
This is the pipe I am refering to, I have seen them on a lot of bikes here in Australia, I figured if this is used then it could get over the hump and fill both sides simply by overflowing into the other side, it only has a hump of around an inch or two, then it it is one large tank from there on. 20200113_104839.jpg