I have a Husqvarna YTH2148 with a 21hp briggs els 656 v twin. The problem i am having is that when it is idling or running at full throttle, the mower sputters. It also spits out flames on the right hand side exhaust in the muffler. I have already rebuilt the carburetor, changed/gapped plugs, adjusted valves to .004, ran premium fuel with sea foam through it. Does anybody have any suggestions. I have also checked the timing key and it is not sheared. I dont have any vacuum leaks around the intake or carb.
