I`m considering removing the tool box from under the seat of my Prairie 650 and replacing it with a hand fabricated auxilary gas tank made of aluminum.

It will basically be a little longer and taller plus slightly deeper (2.5 inches) than the tool box. This will add just under 2 gallons of gas. The tool box holds 1.5 gallons of water incase your wondering. I could go a little deeper but I want to stay well clear of the swimg arm travel. I have measured it all out and made a print. I`m now making a cardboard mockup (sp) before cutting and welding anything.

My delema is how to tap into the existing fuel lines. Here are the 3 options I`ve considered. This is where I need some help because I`m not sure if either will work effectively.

1. Simply T into the fuel line between the tank and the petcock.
My hope is that the fuel will be drawn out of both tanks at the same time draining the smaller auxilary tank first then from the original tank seemlessly. I don`t know if this will happen I`m only speculating.

2. T into the line same as option 1 but put a valve in there that will need to be switched like a pick up with dual tanks. Down side is not knowing when to switch or switching when it runs out most likely not at a good time. Also the possibilty of an air pocket in the line since most of the tank will be below the petcock.

3. This is the least appealing because it requires drilling the original tank but may be the most efficient route. Connect both tanks at the bottom via a hose from one to the other. Since the bottom of the auxilary tank will be higher than the bottom of the original it will gravity feed the other. Assuming of coarse I can find a fitting that can connect to the original without going inside.

I`m sick of bunge cording a gas can to the rack and having to worry about it falling off which it usually does with way I ride.

If I do this I will be taking pictures with some instructions and prints to post, possibly on NYROC`s site if he would be so kind.

 

I'm not too sure what the best way to go is, but I had my insurance card and title in a plastic baggy in the trunk. After having to go in there one time I pulled it out and the bag was partially melted. Just warning you incase the heat might be too much.

 

That is funny, I was just talking about doing the same thing the other night. I was thinking that if I could do this it would give us more gas for the 12 Hours Of America race. My thought was to run a line from the factory tank to the remote tank so that the fuel gauge would read right as the 2 tanks drain. If you do get this made up before I get the chance to I'd be very interested in buying one from you.

 

I'd go with option #2. You gotta remember, the 650 has a fuel pump, it's not gravity fed. I think this would be your best bet. I would put some kind of heat reflector on the exhaust side of the tank to protect it. Other than that, it's a darn good idea!!!

 

I believe you will have to look at the fuel tank a little closer as there is a fuel pump inside the tank which produces a positive pressure. This pressure is read only from our fuel sensor if the pressure changes the fuel sensor sends a message to the cdi unit telling it to shut down. Only by turning off the quad letting it go through its little sounding ritual and turning back on will the fuel sensor reset itself. You will have to put in another fuel pump along with your extra fuel tank. I have tried this before with my turbo setup and the quad will shut down trust me. You can put in a electric fuel valve actuator so at a flip of a switch you can have your auxiliary tank working supplying you fuel. You will have to have your secondary fuel pump working before you switch so there is no interruption on the fuel sensor. Have fun!!!!!

 

So if you ran a line from the bottom of the spare tank to the lower portion of the factory tank the spare would gravity feed to the factory tank,,,, correct?? So in theory, this should have no affect on the fuel sensor and would eliminate the need for a pump for the spare tank,,,,,,,,, or am I thinking wrong? This would be option #3 in the original post

 

We looked at the tool box area to for my brothers 650. Didn't want to fab a tank so opted instead for a 3 gal tank mounted on the rear of a rack extension. We had the same thoughts on how to tie it all in and opted for your option #2. Tieing the two together as one tank has two potential problems: 1. With uneven drain levels, you might wind up sucking some air. 2. If the 2nd tank is higher than the main tank (as it is in ours) there was the chance that gas from the aux tank would vent out the main tank cap.

We usually wind up just filling the main tank from the aux tank if we stop for a break. If you put the valve in the right location, you could reach it while you wre running. Keep it simple, just watch for when you hit 3 bars on the fuel guage and then open the aux valve.

My .02 worth

Jaybee

 

Yes, should work good so long as the bottom of your secondary tank is higher than the lowest portion of the primary tank if you are emptying from the bottom.You might seriously look at a secondary fuel pump pulling from the top or just off the bottom of the secondary mostly for reliability with respect to moisture in either tank. Sounds good though, need a welder?

 

The heat from the exhaust was a concern of mine as well. I was going to add another heat shield between the tank and the factory heat shield. The factory tank is about 1.5 inches from the exhaust with 1 shield at it`s closest point. There would be about 1 inch between the second heat shield and the auxilary tank. May even add heat tape for added piece of mind.

I may try option 1 first it`s simple and can easily be returned to stock condition. I`m speculating that a syphoning effect will be created.

alltoys
Where is the sensor in or out of the tank? If it`s in I would tend to agree with prairiewrench that gravity feeding the tank from the bottom with the auxilary tank would not effect the sensor. If it`s out and in the line someplace I agree that if I got an air pocket some how or low flow that what you said could happen. You`ve been playing with the P650 a lot longer than me so I`ll heed your warning. Thanks for the offer but I have several to choose from at work and they love doing "government " work if you know what I mean.

Thanks !!! but it`s time to sleep now.

 

Easteregg

I am always on the go LOL. The fuel sensor is on the body not far from the carbs a little pain in the neck sometimes. If you use a fuel line that is larger than supply it should drain with some speed. There some stuff for a hest shield that works excellent called ceramic wool it comes in a blanket form can be cut then installed with heat tape. This stuff is so resilient to heat you can hold a bare hand on one side and a tiger torch on the other and you will not get burned, ausome stuff. Your welder buddy will probably know of it have fun till later.