[patrickt]

And there are two easy ways to check for vacuum leaks. First, just get a mirror and angle it so you can see under the base of the carb and look to see if the port tubes have lost their little black rubber cap. The second way is to have your engine idling and use a butane torch that is not lit to spray gas around the base of the carb while it's idling to see if it revs up by sucking the gas in. But for now, let's just stick with the first way.