Auxiliary fuel tank on M7

[High Life]

I have a custom built fuel tank form my M7 that I am trying to plumb in and am wondering what kind of fittings I need. This tank works off the vacuum created when the factory tank cap vent is plugged and the factory tank is forced to vent through my auxiliary tank. The previous owner had great luck with it but didn't provide me with all the fittings it appears I need. I think I need a brass tee fitting to tie into the fuel line right after it comes out of the tank, but does it need to be anything special like a check valve also? The previous owner is out of contact for a couple weeks so I'm looking for anyone who has done this sort of thing on M series sleds or Crossfires....

See the attached photos.

 

[sledhead699]

sorry dont know what fittings u need. but how much fuel does that thing carry. i bet it a little nose heavy with that setup.

 

[spomey]

Dude, no offense but maybe rethink this, a gas cap right above the exhaust. dude if you roll over and have a leak.......what if the sled is on you? and you cant get away....

be safe man just strap it on the back, if needed put the gas in early then bury the can and get it on the way down.

Just cuz ya can do something doesnt mean you should.

Be safe.

Spomey

 

[alexhack]

Ya, what spomey said. Not the safest idea having HOT exhaust right next to fuel. The extra weight would suck too. And your gas would heat up losing you some power. (not much but a little anyways). Ditch the setup, lose the weight & the risk.

 

[G-Force]

ditto, either that wear an asbestos suit making a touring sled outta that? i think i can fit an almost 5 gallon can on my rack on the tunnel, means more crap i gotta carry in my backpack, but i'll take sore shoulders over first degree burns lol...

 

[McustoM]

I'd think it would be safer to extend the tank back towards the seat. possibly a custom seat/tank. It also seams that that heat will affect the gas in the tank. Not trying to bash on the aux tank just my opinion.

 

[Evolution Powersports]

If you haven't done so, remove the plastic insert that protrudes down from the filler neck into the tank. This is good for about an extra 3/4 of a gallon. We have done this on all of our M sleds with no ill effects.

 

[furthur]

... I think I need a brass tee fitting to tie into the fuel line right after it comes out of the tank, but does it need to be anything special like a check valve also?

That won't work. That line has fuel at 40 psi in it (the pump is in the tank). I'm not sure how you'd make that work without another tap on the tank, and maybe a transfer pump.

I agree it looks risky, but for those who are worried, check out how close your stock fuel line is to your pipe, right at the tank...that one has worried me for awhile. I keep foil tape on it, anyway (makes me feel a little better).

John

 

[PCDOC]

WOW!! I'm all about the Rube Goldberg inventions myself, but that one scares me. You couldn't pay me to ride a sled with that thing on it.

Don't mean to bash, but rethink the idea before you actually install it.

 

[High Life]

I finally got ahold of the previous owner and to plumb it in and found out I need to drill a new hole into my stock tank and use a fitting that has a rubber grommet to seal around the new fitting like they used on some old Cats. After thinking about it, this makes alot more sense than a T in the fuel line going to the throttle bodies since that line is pressurized..

This tank was made for some racers running in the Iron Dog here in Alaska. They had very good luck with it and no issues to speak of, which says quite a bit since it is quite a grueling race. However, you do bring up some good points that it could be a fire hazard. The heat from the exhaust doesn't bother me so much as any fuel possibly leaking out of the vent and somehow getting close enough to the can.

The tank holds about 3.4 gallons and I like the idea of having the weight of the fuel more centralized rather than sitting on the back of my tunnel. I have always had plenty of fuel on previous seasons riding in Montana but here in Alaska, it can be a long ways between fueling stops. I have a friend's cabin that we ride into and it is 70 miles one way in. There are villages to get fuel, but since I am running a big bore, I am a little leary of the quality of fuel at these places and how long it has been sitting there so I try to minimize the amount that I buy.

Needless to say, I'm still on the fence whether it is worth it for a couple long rides a year when most of the time a 2.5 gal can on the tunnel is enough. I don't know about anybody else but the mileage on my M7-8 is pretty poor. I've burned through a full tank plus 2.5 gal in 87 miles and had to get towed 1/4 mile to the truck.