Hi can anyone help . I'm a new rider and have bagged myself a gas gas txt pro 280 2002 model. I've done loads to this bike since I got it a month ago. Discs , pads , full service , bearings , chain sprockets and much more. When I'm pottering about on it though it seems a little jerky at low revs in low gears . .ive stripped the carb down and all jets are spot on and clean ans chain seems tight enough. It's almost like this beast just wants to go all the time. Is this normal. Any help much appreciated . Chris