My '02 YZ426 has developed a stall right as you blip the throttle. The engine is aleady up to operating temp and it's usually when I pause for other bikes to catch up on the trail. I blip it a time or two and before I even grab the clutch and it dies, I have to hot-start and there goes my lead. I've had the carb apart recently so I don't think it's trash in there but I can't figure what else. It's actually done this from the start but a lot more recently so mabey it's a jetting issue?