The past week my friends Banshee takes a bit to start. Everytime while kick-starting it, it back fires .. making a loud pop sound. After it finally starts, more smoke comes out of one side of the pipes. When sitting in idle, it makes a whacky clunk sound. While riding it, it moves, but their seems to be some lag in power aswell with back fire pops. The bike is worked and was purchased a few weeks ago. The previous owner never change the rings. So Im wondering if new piston rings are needed .. or maybe a cracked reed valve? Any help or suggestions is greatly appreciated.