I have a 2004 lt-a50 that my son has logged about 100+ hous on. Its a great little quad but lately Ive had trouble cranking it and it stalls when stops. So I idle it up, he rides a while longer, then its to high to stand still with out the brake. I think the problem is difficulty setting the idle screw and air screw.I tinkered with the settings to no avail. Warm up is fine with choke on (high idle) but with choke off, I cant get a stable idle speed that doesnt either die or engage the clutch. Any suggestions? What's a good starting position for these screws and how do I achieve the "perfect balance" between the two without bogging??? Help!