I get a knocking sound at idle when the bike first warms up and is running a little rough. I always goes away when I raise the rpms or when it warms up. I was thinking that I might have a clogged lifter. Any ideas?
As 2580 said, clean and sync the carbs first. You might try some SeaFoam in the fuel at first and see if it cleans it out. It is not my favorite but it's quick and cheap. The lifters usually make a clicking sound and not a knocking one and it's easy to recognize since it's coming from the head.