You might take the high speed needle out and see if the mini o-ring is in good shape as well as the carb sealing o ring. While its out make sure the fuel path is clean. I take it you have new fuel and not 8 yr old fuel. Are you using a stock Webra muffler??? As you look in the carb does the smaller diam rod approach the center of the larger diam rod when closing the throttle?? It should. I always assume your fuel and pressurization lines are not kinked and not leaking. I got both of my Webras from Natl Hobby in Ga so I don't know of any URL's