Ok, Update. Now at a 90 main, top end is nice and clean, no more of the jerking. Im at the 2nd notch from bottom for the needle, but the take off hesitates. I get the best response from the throttle with the idle mixture screw 1/2 turn from completely closed...that is I sign I need to lean out the idle jet, right? Might have to go back to the 45....