What\'s the problem here????? My 305 runs real rough when I first start it up. Almost sounds like it's not firing all eight cylinders, but it eventually smooths out. I thought it was due to the cold mornings(30 degrees) but I started it this afternoon(65 degrees) and it ran rough. I need to increase the idle 'cause it's at 500 right now. Would that solve the problem? The carb is about 3 weeks old. Also it puffed out black smoke this afternoon, but it wasn't a lot. Thanks for your input. FUN WITH 31's!