Auxiliary Fuel Tank for Travel

[Turbo Ghost]

Here kicked my stupidity in .... should not try to play with the big boys.
Yes, got you.
Anyway, do we THINK or do we KNOW if the head pressure to the cap is an issue for a 2.5 gallon tank?
When the pressure increases, (when the fluid expands due to i.e. heat), it will push the gasoline back to the secondary tank I believe, unless the head pressure caused by the secondary is >threshold. (I'm mixing two different topics now ) and there is no movement in the system (not running).
But let me ask a different thing, back to the fuel line.

When the engine runs and the secondary tank cannot deliver the same amount of fuel per minute what the engine is consuming, would mean, the main tank gets emptier over time, but there would not be much pressure to the main cap, as the main tank is not full unless the engine is not running, right or wrong?

So the diameter of the fuel line could be something to consider. *twisting head*

Apparently, the head pressure isn't an issue as I haven't seen any comments from the ones who've directly connected the aux to the main about leakage. The head pressure is roughly 0.3psi so, not too much pressure. For your second query, I can't imagine even at full-throttle the aux fuel line wouldn't be able to keep up with demand. I don't know what size line the vent tube takes but, I would guess maybe 5/16" or so and that should flow plenty to keep up. Yes, I agree expansion when not running would push fuel back up into the aux tank but, the pressure would be same as head pressure unless the aux tank vent failed. THEN I think you would have a problem! Otherwise, I think everything will be fine. It's really all a moot point for me now as my plans for a gen 2 fell through and I decided to adult instead. I just ordered a 14x40 portable building to become my workshop so I can finally have a place to store and work on all my bikes instead of letting them sit in my carport rotting away neglected! I can't do projects that take more than a day as loose and open parts are exposed to the elements and I have racoons and other critters that like to steal small, shiny things! Once I can get my shop set-up and start restoring some bikes I'll sell some and hopefully before too long I'll join the gen 2 club!

 

[crynool]

Wishing luck with your plans and I will see what I will do this week for my Max.

Yesterday, I played a bit with the throttle while on the highway and the mpg display went down to 10.5mpg ....
I'm close to believe, pouring the gasoline from the can to the street is much slower.

 

[Beau254]

This is exactly what I've been considering but, in the videos I've seen everyone is connecting to the vent tube at the filler neck and that makes no sense to me. Unless I'm understanding it wrong, the vent/breather tube is to allow air into the tank to replace the fuel that is consumed and to allow for the release of gasses during heat expansion. If you use this tube as your filler there is nowhere for the air to go when you fill it up. Obviously, it appears to be working for people but, I'm not understanding why? Thoughts?

They put a breather in the auxiliary. Because it feed to the primary tank. So then it vents the whole system.