Ouch Daryl...That is one that I haven't done yet. I could though. My new Venus II has the tank up against the firewall. I flew for 10 minutes and noticed that I needed some down trim. I got it re- trimmed and landed, fueled up and went for takeoff again. I really scared myself as it took full up to lift off and half up to fly level. Needless to say I re-trimmed and pressed on. That is the first time that I have ever noticed a trim change from full to low fuel. The tank is only 14oz. I do love the Venus and really like the OS 120AX. That engine runs very smooth with tons of power, and the throttle response is awesome.