Does anyone know where schematic on this engine or in general a 98 Exmark 36 inch Metro. As I've stated in other post My machine starts hard and every so often while idling the rpms change, nothing too drastic just enough so you can hear the engine sound change. Almost like its not getting a constant flow of gas. even when I engage the blades it does this for 2-3 minutes. The carb has been rebuit already by a local dealer and I think it just something to do with the choke!