Re: Slow to come down to idle when warm / hot
 

Ah HA! Now for the REST of the story! :roll:

That opens up more possibilities.
Like head gasket leak.......
Checked the valve clearance lately??
If everygthing else checks out, the rebuild might have changed the displacement JUST enough that you need some carb mods to get the mixture right again.

Re: Slow to come down to idle when warm / hot
 

Yun:

In addition to all that has been mentioned, if your idle mixture screw is causing the engine to idle too lean, then it will also cause this condition of not returning to idle promptly when the throttle is shut. In the N/A bikes, the screw is under a brass plug that needs to be drilled out before it can be manipulated. Turn the screw counterclockwise 1/4 turn at a time to richen the mixture, and check the results after each adjustment.

-Rich