The other day I was checking my lines and doing some things to make sure I'm not getting air in the lines. What I noticed is...where hose goes connected to the fuel moduel bracket( 90* screw on plastic connector)...there is still air in that chamber. Since I run 50:1...the gas is a little dark. So...I can see through the plastic and see where the level of the gas is going into the chamber. It looks like there is still air in there. I thought the vacuum operation was supposed to suck all the air out? I know it works...cause I bought a new vapor pump about a year ago and I can feel the pulses when I put my hands up to the hose that goes into the carb cover. Am I getting trapped air in there or is that(gas level) slowly supposed to come up and fill the chamber as you accelerate?