Re: Need some help and advice......
Your lower tank fuel cap is surely vented. If you allow a top tank to freely flow into the lower tank, it'll overflow out of the lower tank cap vent.
If you wanted to have a continuous flow, you'd need to have a non-vented cap on the lower tank, a vented cap on the upper, and the tube between the two always open. Even so, you might have flow problems from the upper tank to the lower unless you had a vent tube from the lower tank to the top of the upper tank.
Edit: Of course, if you only use the top as a reserve, and keep the vented cap on the bottom, then you'd only have to worry about the one tube. Just close the petcock between the two before the lower tank overfills.
Last edited by Nougat; 02-28-2010 at 07:01 PM.