Small Engines (Lawn Mowers, etc.): Craftsman lawn tractor carb problem., craftsman lawn tractor, doesnt work

Question
I have a craftsman lawn tractor moden 917.270821 that has developed the following problem: The engine will not slow idle without choke. When full throttle is applied, about 3/4 choke is required for smooth running. If choke is not used at full throttle, the engine continuously revs up and down. I have changed the fuel and air filters to no avail. I get the shivering fits every time I think about taking the carb apart, cleaning it, then trying to get it back together properly, so I would feel a little more inclined to attempt it if you thought it was necessary, and perhaps had some tips.

Thanks,

Stew

Answer
 Hello Steve:

 Regrettably the Model of the Mower doesnt tell me the Make, Model and Engine Size. If it has a Slotted Screw in the Bottom of the Fuel Bowl, then Turn the Screw Counter Clockwise 1/4 turn at a time until you no longer need the Choke for High Speed. This may cure the Idle Also. If Not, then Find the Screw that is on the Side of the Carb. Turn it 1/4 Turn Counter Clockwise. If this Doesnt work then the Carb will have to Be Cleaned and Overhauled. Hope this Helps.

 Good Luck

 Respectfully

 John