Hello and welcome to Just Answer,
What are hte model numbers off of the engine? How did you clean and rebuild the carburetor?
MODEL # XXXXX SPEC #69525
I disassembled it completely and used areosol carb cleaner. It was fairly clean in the bowl and the carb itself. The rt bank cylinder had both valve rockers off. I reinstalled them and properly torqued them. This mower has been sitting for at least 3 years in a garage. It idles great at low speed and the PTO can be engaged at low PRM with no problem. As soon as I increase the engine speed it idels irradically.