I have a 7720 with the 466 in it and today I went to start it (been sitting for a year) it fired right up with lots of black smoke and went to high idle app 2600 rpm...... I pulled the kill switch out and it never slowed the engine down a bit. I finially had to go shut off the fuel at the tank to get it to stop running, all the time no mater where the hand throttle was place, it ran wide open.    What could possible be wrong? it ran perfect last fall,  You talk about scareing the crap out of you when you cant shut down a run a way.....  help.