To fill the on-board tank, first make sure you hold the supply roughly straight up, go ahead and fill the tank once and then dump it back out by removing the check valve festo, then quickly put the festo back on and refill it again. You will notice that it will take a lot more the second time. What is happening is when you fill it the first time you have a lot of warm air in the tank so most of the powermax vaporizes as soon it goes in and you get little of it. When you dump what little you put in the first time, the tank gets cold and most of the air gets displaced. When the tank is cold the powermax will remain a liquid and you get more in on the second shot. The tank holds plenty, don't worry with a bigger one. Make sure you let the tank warm back up before you start the engine, or warm it with your hand. You need the powermax warmed back up so that you have good pressure.

As to the fuel leak, where is the fuel coming from, the tail pipe, the inlet, or from the seam between the cowl and the can?

Steven