Ruff running motor

[dmc1620]

I have a Gravely zt xl 52 mower with Kawasaki Fr691v engine. It seem to run good when cutting grass at full throttle but starts to run ruff as soon as the pto stops. Runs worse the slower you run the motor. Has new air filter, new fuel filter and new plugs which didn’t help. I sprayed some carb cleaner with it running which also didn’t help. Any ideas what I should try next? I also have a Cub Cadet with the same engine that runs smooth at all speeds. Thanks for any help.

 

[hlw49]

Sound like idle circuit not supplying enough fuel. Try pulling the choke slowly until it levels out. If it does that is your problem. Carb needs a good cleaning.