Some time ago, it became obvious that my Lyc 360 Bendix fuel control was gradually becoming more rich at idle.  The old greybeard mechanic told me that the moving parts in the unit become slightly scored with age and allow more fuel to pass.  Also, he reminded me that a properly adjusted control will allow the engine to idle 50 RPM faster before shutdown as the mixture is pulled.  The real trick is to do it slowly.  Set your idle speed exactly to 600 RPM and creep the mixture back.  If your RPM peaks out at 650 before roughening and loosing speed, you are all set.  If not, go turn the little wheel on the bendix.

Since doing this my engine seems to run better all the time - not just on the ground. Less carbon I suppose.

Mark,

 

Yes indeedy.  And, if the adjustment does not work, it might be time for the dreaded "throttle body overhaul."  A procedure that uses money to correct the problem of aging.  Too bad it doesn't work on my own body.