On my 026, it seems I can't set the idle low enough to keep chain from moving. Just about where the chain stops, the motor just barely wants to run. I believe the carb is set right, seems I might have a clutch problem. Took off e-clip, sprocket and drum. Some crud built up in drum - cleaned it out. Found that the drum has a groove in it that must fit in a "tang" behind the clutches - I don't understand what this does. Seems that the "tang" will rotate just like the drum so what is it's purpose? Is this likely my problem causing my clutch to stay "hooked up" at such a low rpm? Or am I missing something way more obvious?