I have replaced battery, spark plugs, wear ring, cleaned carb, cleaned rave valves. I start it up and it idles at 1500rpm. When I give it gas, rpms go to 3000 and stays there until letting off throttle. It makes a dadadada (lol) noise during. After idling for about 10min it runs perfect. If I turn it off, wait a couple min it goes back to that same warm up thing. What is causing this?