ok i had a look at the tank lastnight and all i can say is whoops. The fuel fubing has slipped off the brass tube by 3 - 4 cm's, causing the clunk line to be longer than usual. The clunk could move around the tank, but the clunk when inverted would press up right against the back of the tank, which i think obstructed fuel flow into the clunk could this be? well anyways i have fixed that, and my clunk looks like its ok, and the tubing is soft enough, i might replace it with the blue aerotrend stuff soon. If this does not fix it i will have a look at my needles. I still have not tached my 22x8 on the DA-50 im just tuning to get rid of the high end burble, so it might not be lean enough, still a new motor though...