20 1 1 Year mark 408 The hand throttle is not turned off.

20 1 1 annual standard 408 manual throttle does not close because there are many hollow pipes on the engine, or the pipes are out or damaged, or the throttle, idle motor, air inlet and seal are not good. When testing, block the throttle with your palm. If the engine can turn off normally, there is no air leakage. If the engine does not turn off, it means there is air leakage. If it is normal, the outside air can only be inhaled from the throttle. If there is air intake in other places, it will exceed the normal air intake and lead to travel.