GT235 john Deer briggs stration engine idles rich and fouls out the spark plugs.

[biggbob]

I have a 1999 J D GT235 B.S. engine that starts right up and cuts the grass just fine at high speed or full open throttle but if I cut the throttle down to idle it wants to run rich and then it fouls out my spark plugs. I put in a new air cleaner and new plugs and it will do the same thing again right a way. I have to always run it at full throttle then when I shut it off cut the throttle back to idle the turn off the key right a way and that way it keeps me from fouling out my plugs. Any body have any ideas as to what the problem may be I sure would appreciate any help with this problem. Thanks Bob

 

[EngineMan]

Its on the fuel side so have the carb cleaned and reset or replace it.