It can idle at 1500 RPM, no problem. Problem is...well, I don't know how to say it in that particular technical language, but I'll try. problem is: it feels like the carb is resetting itself "to defaults". E.g.: I adjust the idle screw, it idles fine. Then the next day I start it with choke, warm it up, ride, it cuts off in traffic again. I adjust the idle again and it's OK for a day. The next day - the same thing. WTF could that be?