Please help. I ride Michigan single track woods trails for recreation. BIKE: I just purchased a used 2003 Yamaha yz250f with a Lectron carb installed, and a Yoshimura TRS exhaust. The Lectron carburetor has only a few markings; patent 4008298, a number "44" stamped onto the thin vertical upper portion, and a "Pure Boost" sticker fixed to the thin vertical upper portion. Can't find a specific Lectron model number anywhere. :bang: PROBLEM: The bike's idle is very high, and has great accerleration from that high idle. This might be desirable for racing, but I'm trail riding and with the high idle there is no engine-brake into the corners. When I reduce the idle to 1900 rpm, then the bike stalls upon attempted acceleration from a stop. Also, the bike starts very hard after each stall - 20 kicks, but starts 10 kicks cold. New spark plug is black, but not sooty. NOTE: Lectron customer service is absolutely useless!!! They wouldn't give me the time of day. HELP: Please advise. What are the default carb settings? And how should I re-tune this carburetor for normal idle and smooth roll-on power? Current C=52.5 mm and idle screw is 2 turns out.