Since it has been getting cooler, my bike has started to kinda act funny. When I blip the throttle it will rev up, then the revs will go down, but not all the way. When I mean not all the way, I mean that after I blip it when I let off the throttle it sounds like the choke is on. Then after a second or two it will go back down to idle. I am assuming that this is jetting related. Do I have to bust the carburator open or can I just richen up the fuel screw?