[Mitch//pa]

You mentioned that you cleaned the idle needle? I think you might mean the idle air adjustment needle. That needle screw adjusts the air / fuel adjustment at idle ( rich/ lean) and does not adjust the actual idle stop. The idle stop screw is shown in the picture
There are many things that can intermittently cause the idle to be slightly raised.
As Marshall mentioned tight linkage pivots or a misadjusted manual hand lever can cause it.
A weak or broken return spring on the linkage
I also had a worn throttle shaft cause int higher idle..
Disconnect the throttle linkage from the carburetor and feell the strength of the return spring it should have a strong return tension as well as for free linkage movement.
If all this checks out when the idle sticks again try manually pushing the throttle against the idle stop screw. If it goes lower then replace the throttle shaft with an oversize one.
I hope all this makes sense