barrett

you may have to go up on the pilot. You mentioned bottom end to mid-range, at those locations the pilots and needle/jet have the most to do with performance. One way you can check to see whether you're too lean or rich is when you begin pushing the throttle with the quad in gear ( to load up the engine) try pulling out the choke half pull. If the quad runs better, your too lean in that range, if it runs worse, your too rich.