It won't idle smoothly with choke on(closed). Revs up and down between 4k and 1k. With choke open, won't idle at all. Cleaned carb and jets. Also replace air filter, fuel filter and spark plugs. Any suggestions?
Might be that the ports (passages) inside the carburetor's body itself are plugged.
With all jets removed spray carb cleaner thru every port until you are sure all are clear. Sometimes you have to 'soak' the carb body in a cleaner to get the ports to clear.