My Scag Tiger Cat 2 61 inch with 29 Kohler EFI is having issues. When starting sometimes it sounds like it on one cylinder until it warms up. Main issue is it run strong until the PTO is engaged then it starts popping and sputtering. This happens even when I am on concrete with the deck up also. It would die when it happens mowing grass and it does this at random ties. I have changed the pulse fuel pump, fuel filter and air filter. I can pull off the plug wire at idle and know that they are both firing then at least. Unit has 350 hours on it. Any help would be appreciated.