Hayabusa Aux fuel system - tested and completed!

[Justin]

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.




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.



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.



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.



Tank re-installed showing the fitting on the bottom.



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



After all the plastics put back on.



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

[veefer800canuck]

Stink finger.  


Well, if you're riding in areas where you expect to not find fuel, then I guess this is useful.

Me, I can get ~350km from a tank on my VFR if I'm careful, that's 218 miles.

I'm usually needing a break after 3+ hours in the saddle, so a gas station break for some rehydration and a snack or maybe take a whiz is most welcome indeed!

[Justin]

Stink finger.  

What? It's a legitimate test!  

Well, if you're riding in areas where you expect to not find fuel, then I guess this is useful.

Me, I can get ~350km from a tank on my VFR if I'm careful, that's 218 miles.

I'm usually needing a break after 3+ hours in the saddle, so a gas station break for some rehydration and a snack or maybe take a whiz is most welcome indeed!

This is purely done with endurance/rally riding in mind. Without aux fuel it's hard to be competitive in a rally where everyone else does. Also, after my BBG1500 I am wanting to do more, and of course do bigger miles in less time. Stopped time on my last one is what got me. Did 1550+ in 23 hours with no fuel cell, as I had to make 9 fuel stops en route not including the start and finish. If I cut out four of those stops, would have been less than 22 easy. I am planning on a BBG3000 next year, so this is a must. If I can cover 1500 in 21 hours both days, that means I can sneak in 4-5 hours sleep in the middle.

As to hydration, that is covered as well. Will be mounting a bag to hold my water bladder on the tank

[Specter]

looks good!

btw, do not trust tourtank's gallon rating. They are completely unreliable in that regard. Otherwise they are an awesome value.  My 5 gallon is actually 4.73g.

[Justin]

looks good!

btw, do not trust tourtank's gallon rating. They are completely unreliable in that regard. Otherwise they are an awesome value.  My 5 gallon is actually 4.73g.

Thanks

And that's fine if it's a little off, and I expected that the to be the case after reading the "Please note that all liquid volume amounts are approximations" on their site  

It will still give me the range I am looking for, 350-400 miles. Thanks for the feedback.

[scottzilla]

Why do I think this will end up as a 150mph flaming streak across the horizon?

[Justin]

Why do I think this will end up as a 150mph flaming streak across the horizon?

Thanks for the words of encouragement. Nah it's all good and safe, and everything is being put together to high standards. Plenyy of bikes out there with aux cells without any problems.

[Mesachie]

Good write-up so far, Justin. Am looking forward to your maiden test run to see if gravity works well enough
to fully empty the aux tank.

[Justin]

Good write-up so far, Justin. Am looking forward to your maiden test run to see if gravity works well enough
to fully empty the aux tank.

Based on my initial measurements it should be fine. The bottom of the aux tank is only one inch lower than the top of the main. So there should be no issues transferring everything. I will update when completed.

[Specter]

It sure puts a smile on your face to see the fuel gauge go up

[Justin]

Some progress today between the 50 other things. Got it "mocked up"  - seeing how everything fit together.



Can't even see it from the back  



Hopefully tomorrow will have it all put together - then I can trim the mounting plate and clean everything up.

[st2sam]

WHOA...
Justin I'm impressed, great job so far. Now if it works?
Your really serious about LD riding, great.  Warchild isn't getting any younger.  
I can't wait to see the end results, thanks for the write up.......

[CLAY]

Good write-up so far, Justin. Am looking forward to your maiden test run to see if gravity works well enough
to fully empty the aux tank.

Very nice work man!  

[Justin]

WHOA...
Justin I'm impressed, great job so far. Now if it works?
Your really serious about LD riding, great.  Warchild isn't getting any younger.  
I can't wait to see the end results, thanks for the write up.......

Thanks No reason it wouldn't work. I had a similar setup on the XX with a Jaz cell that worked fine. It's all gravity, nothing complicated; if one tank is lower than the other gas will flow to the lowest point.

As to the other comment, I'd not go quite that far  - he's in a league of his own, and has records that will never be beat  

[Justin]

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  



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.



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




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.

[scottzilla]

Looking good.  Shooting for 500 miles between fill ups?

[Justin]

Looking good.  Shooting for 500 miles between fill ups?

Not quite  

350-400 is more realistic

[Justin]

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  . They advertise 5 gallons for the size I ordered (10”x20”). So I got an extra gallon. No problem, I'll take it  

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



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  

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 tank and hardware).

Edit to add - the weight of the aux tank had a negligible affect on the bikes handling/ride when full. It's like having a 5 year kid riding on the back, since the tank is mounted right over the pillion area.

[scottzilla]

How nature says "Beware":

Busa rider flying down the hwy nestled between 11 gallons of gasoline.

[Justin]

How nature says "Beware":

Busa rider flying down the hwy nestled between 11 gallons of gasoline.

Oh ye of little faith   - Don't be such a hater.