Gen2 Aux fuel system - part one complete

jphilipson

Registered
Finished up part one of my aux fuel project - plumbing everything for the main tank and routing to the aft.

Tomorrow I will mount up the 5 gallon Aux cell (Tourtank) and connect to the system

This is a 100% gravity fed system. The aux tank is higher than the main - so wait till the main tank is almost empty, throw the valve, and gravity will back-feed the main tank. System is 5/16 fittings and fuel line.

Was originally planning on using a bulkhead fitting, but the tank openings are way to small to correctly install one. I could not even get a hand halfway in the opening, never mind get a wrench on the fitting inside. So rather than risk a bad connection, I decided to go the weld-on bung route.

Tank and rear plastics off - fuel line laid in place.

IMG_0561.JPG



3 washes with soapy water, then letting the hose run through the tank to rinse it for half an hour did the trick. Killed almost all gas odors. After washing the tank multiple times , I dried the tank with a shop vac, then rags - Then let it bake in the Colorado sun for the rest of the day.

By late afternoon it was ready to get the bung welded in. Got referral from a friend on another forum, and the guy hooked me up. He runs a race team out of his shop, and is a much better welder than me :)

This is a 1/4 NPT threaded bung welded into the tank.

IMG_0566.JPG


A little closer in. The rough spot was due to some contamination causing the weld to bubble out. After regrinding a bit the weld took better.

IMG_0565.JPG


Got the tank back together, fuel pump assy back in, and elbow 5/16 barb into the tank. Threads sealed with TFE paste. The tank fitting also made a nice retainer for the tank's heat shields.

IMG_0567.JPG


Tank re-installed showing the fitting on the bottom.

IMG_0568.JPG


Rear of bike, under passenger seat showing the qucik disconnect fitting to make tank removal a breeze.

IMG_0569.JPG


After all the plastics put back on.

IMG_0570.JPG


After getting everything back together I put the ~1/2 Gallon of gas I had drained from the tank back in and headed down to the gas station to fill it up. I also added some crap to remove water from the fuel as a precaution after having washed the tank. The tank baked in the 90 degree sun all day after being dried with the shop vac/rags, so this was just a little added protection. After a quick ride with the tank full, I double checked everything, and no leaks anywhere. Finger tested everything and no stink finger.


That's it for part one. Everything is plumbed and ready to go for part two - getting the aux tank mounted on the back and hooked in. I pretty much have everything ready for that tomorrow (wood template drilled etc), so will be pretty quick. Just need to drill my mounting plate using the template, and attach to the existing rack.

Part two coming soon :)
 
Almost done now - just a few small parts to clean up. Need to trim and paint the mounting plate and hardware. Need to find a good place to mount the puke tank and vent line. Other than that it's pretty much done.

From the side, looks big, but it's no wider than the tail bag. Ignore the mess in the garage :lol:

IMG_0576.JPG


Looking over the tank bag from the front. Had a piece of closed cell foam that used to be a butt pad (like for ball games etc). I used the mounting plate from the hump, and trimmed the foam pad to make a gasket around the plate - to cover up the hole where the rear seat/hump normally goes.

IMG_0578.JPG


From the rear, can't see the tank past the tail bag.

IMG_0577.JPG



That's pretty much it other than a few things to clean up. The plate is mounted with 2 stainless U-bolts and 2 stainless 5/16 bolts. Everything is secured with lock washers and nylon inserts nuts. The mounting rings for the tank use 4 5/16 stainless bolts. The two rear bolts are shared with the plate mounting.
 
That's GREAT! So, how many miles can you get now without having to refuel?

Thanks

I should easily be able to do 350+, maybe 400 depending on a few factors, like how much I can transfer, and how much I can get in the aux tank on the side stand. The aux tank is 4.73 gallons (slightly less than the advertised 5), and the main tank is 5.5.
 
Thanks

I should easily be able to do 350+, maybe 400 depending on a few factors, like how much I can transfer, and how much I can get in the aux tank on the side stand. The aux tank is 4.73 gallons (slightly less than the advertised 5), and the main tank is 5.5.
So where will you be riding where you will need to be able to go 400 miles between fuel stops?
 
So where will you be riding where you will need to be able to go 400 miles between fuel stops?

I'm into endurance riding (Iron Butt etc) and rallies. For example the ride I posted on the URL below.

https://www.hayabusa.org/forum/trips-touring/153357-1550-miles-23-hours-gen2.html

I'll be doing the LOE 1000 rally coming up in 2 months as well.

Basically, the extra fuel allows you to make a lot less stops, and save more time. Not to mention, when riding in the western states, you are frequently forced to stop for gas early, as in some areas there can be 100m between gas. So, without aux fuel, if you were at 100 miles and approaching a section where there was no gas for the next 100 miles, you'd have to stop early to fill up. With the aux fuel there would be no need.
 
I'm into endurance riding (Iron Butt etc) and rallies. For example the ride I posted on the URL below.

https://www.hayabusa.org/forum/trips-touring/153357-1550-miles-23-hours-gen2.html

I'll be doing the LOE 1000 rally coming up in 2 months as well.

Basically, the extra fuel allows you to make a lot less stops, and save more time. Not to mention, when riding in the western states, you are frequently forced to stop for gas early, as in some areas there can be 100m between gas. So, without aux fuel, if you were at 100 miles and approaching a section where there was no gas for the next 100 miles, you'd have to stop early to fill up. With the aux fuel there would be no need.

Aaah, that explains all your hard work. Thanks and good luck on your rides.
 
Great job and looks good!! :thumbsup: Are you going to keep the tank the bare aluminum look or have it painted? I think it would look sweeeet if it was painted to match the bike!
 
Great job and looks good!! :thumbsup: Are you going to keep the tank the bare aluminum look or have it painted? I think it would look sweeeet if it was painted to match the bike!

Thanks, I'll probably just wind up painting everything black, at least the mounting plate and hardware. The tank I will probably leave as is. This project was not done for looks, just functionality.
 
Got it out for the first test today, and everything went well, except one thing; which could actually be a good thing. When Tour Tank says that liquid volumes are approximate, they are not kidding. Filled up the aux tank for the first time today, and it took 6 gallons on the side stand :eek:. They advertise 5 gallons for the size I ordered (10”x20”). So I got an extra gallon. No problem, I'll take it :thumbsup:

This is on the side stand filled just to the filler neck.

IMG_0579.JPG


Anyway, it looks like the gravity system works flawlessly. Main tank was half way into reserve when I filled the aux tank. After throwing the valve, it took 20-21 minutes to fill the main tank just past the full line before I turned off the valve (I have one of those bikes that sits on full for about 70 miles, so it could have taken more). At that point I stopped an checked and there was about 2.5g left in the aux tank (eyeball measurement). Ran 100 miles until the main tank was down to about the halfway again, and turned the valve back on - and it gravity fed it back to full again and was still going strong before I turned it off. Checked aux tank again and it looks like there is still .5 to .75 gallons remaining. Once the main tank drops again, should be no problem feeding that in.

Anyway, looks like everything works flawlessly, and there will be no problems transferring everything from the aux to the main via gravity. Since the tank I ordered holds a gallon more than I expected, that means with the aux tank I have a range over 400 miles easily. Main tank is 5.5 gallons, and the aux is 6. Based on 40 MPG that translates to 460 miles. It also puts me right at the 11.5g limit for the IBR if I were ever lucky enough to get in :thumbsup:

The only issue is that the aux is bigger than the main, so it takes two transfers. I expect if I left it on, it would make the main tank puke out of the overflow, so I have to switch it off when the main is filled. Otherwise, everything is great, and I'm happy with the results :). Only thing I may do different in retrospect is use a thinner piece of aluminum for the mounting plate. The 1/4 I used seems like overkill. It weighs @ 2lbs, although will be a tad less when trimmed up. The total setup weighs in at @ 40 Lbs when the aux cell is full (6 x 6lbs for the gas, and 4 Lbs for the tanks and hardware).
 
Back
Top