secondary fuel tank?

okay. i have an idea and question. and want to make sure its even probable before i go out and start buying the stuff. im making my XJ an army themed bike. and instead of bags i want to hang an ammo box and jerry can...thats the easy part...i want to make the jerry can a secondary fuel tank because the tank on my bike only gets me like 150 miles. wich is mighty annoying. and what i want to do is to try and make it so a fuel pump will pump gas out of the jerry can into the tank when the fuel light comes on, in turn use it as a switch. and was wondering what how many amps dose the fuel light switch use? would it be enough to power the pump? on average a car fuel pump requires around 6 amps. i found some smaller pumps that only require 1.4 amps and pump 34 liters/hour or 9 gallons/h wich might work. if you have any insite it would be much appreciated.

 

I'm pretty sure you'd kill that little switch, PLUS I would imagine it is just switching the ground side.

I like the idea, with two reservations:
Make sure the can is capable of holding the gas with all the abuse it will see bouncing around back there. Also make sure it is SAFELY vented.
That spot is right over the top of those hot mufflers (I'd hate to see a flaming XJ going down the road)

Last thing. Where would you pump the gas into the tank (not terribly tough)
You don't have a fuel gauge so you wouldn't know when your primary tank is full and when to stop pumping.

Maybe you put a timer on the pump. Hit the switch, and it runs for 10 minutes or something??
Let us know since fuel capacity is a PIA on longer rides.

 

use a relay. Power to the light cuts the relay on, sends the power you need to the pump. When the light goes out, the pump will go off. This could make the pump constantly cut on and off, but it should work.

 

check out these links

http://www.tourtank.com/

http://www.tourbuddy.com/bikes.shtml

http://sampson-sporttouring.com/fuel-cells.html

http://www.motorcycle-superstore.com/2/ ... -Tank.aspx

 

I don't know how big your jerry can is.
I've only seen 5 gallon cans.
5 gallons is alot of wieght on one side of the bike.
The idea of a relay to the pump is good.
Of course if the bottom of the can is close to the hieght of the pet cock you could put a simple 1/4" manual valve in the line connected to a "T" in the main fuel line and just switch it over when neded.

 

well they hold up on the back of a couple of jeeps i know down here. and jeeps are bouncy as hell. so i dont think thall be a problem. about the exhaust. i happen to hate it. so itll probly be gone by the time all this happends. and im gunna put a ammo can on the otherside kinda like sattle bags. but not. and i was thinkin about using the fuel light switch as kinda a relay. i think. like whenever it comes on itll turn on the pump and when it turns off itll turn the pump off. but how are you thinkin about the light switch. i think thats a serious possiblity. i just dont really get it. oh and thx for all the advice guys. ive been comming to this site since i got my bike. its an amazing site. oh and i just got a leak on my head gasket...YAY! dose anybody know ware i can get one. and maybe a manual too.

 

My two cents:

The switch will carry low amps and it will activate the relay to carry the high amp draw of the pump.

Use the low fuel light to switch a relay with a timer. Program a timer to run less time than would be required for the pump you do choose to completely fill the tank. (and I would go for lowest amp draw).

You still have the issue of another fluid input into the tank - a new threaded bung maybe. Do use a check valve(s) to not siphon the gas back to the jerry can (which is lower than the main tank)
Pumping the new fuel back through the petc*ck probably isn't a good idea.

Filling the tank too quickly with the (vented) cap closed might cause too much positive pressure on the out-flowing fuel to the carbs. Probably not a big issue if your float valves are very good or perfect.

 

two lines?

have one line for air and one line for fuel(the air line could be pretty small)

you would probably have to tap and weld a pipe fitting to the underside of the tank so it could pump in and one near the top so air could go to the can

the relay on the fuel light is probably a good way to go, but for it to not cut off and on you would need a timer to keep the pump doing its job for a few seconds after the light goes out

you could also use a vacuum operated pump system
just leave it running and have a return line so it could circulate gas once full