Quick question to hopefully an easy issue.. Recently bought a 2008 rzr 800. I bought it knowing it had a couple of issues, one of which the guy said it had been sitting for roughly a year. It sputters at full throttle, so I figured it was just bad gas. I drained the tank, added premium gas and changed the plugs. The problem still exists. After pulling the bed and looking at it, it appeared 1 muffler was warm and the other was very hot, so I suspect 1 cylinder isn’t firing quite right. I pulled the plug from that cylinder and it appeared to have either carbon or dirt on it, reinstalled and had same issue. Any thoughts on what might be the culprit? Thanks in advance.