RE: Fuel Tank Frustration
The trick on tightening the screw in the stopper is to do it over a period of time. Assemble the tank before you actually need to install it, and just snug the screw good the first time. The next day you will find that the screw will easily turn another 1/2 turn. (the rubber is "forming" it's fit into the neck of the tank) Do this a couple of more times and you will have a stopper that does not leak, but yet will not split the neck of the tank because it hasn't been forced all at once and is not too tight.
Also, use 5/32 aluminum tubing rather than 1/8" tubing. It fits tighter in the rubber stopper holes (the tubing does not want to twist when you tighten the screw), and the tank fills and drains easier.
Ernie