i have to press the gas petal down all the way to start it, then idle it a little bit. it hesitates at take offs. if it doesn’t start the first time, it takes a while to get it started again. sometimes i have to let it set for an hour or so. when it starts it chokes and spudders till it finally gets going, that’s with the gas petal down all the way. i changed the spark plugs, fuel filter, and idle air control valve. any ideas?