Looks like the probelm was the air motor on the tb. Removed it, cleanned with contact cleaner, to make sure the plunger assembly was moving freely down then springing back when released. Problem has gone away.

 

Glad to hear that all is well again

 

Got any step by steps for cleaning the air motor?
I'm having the surging / stalling problem with mine.
Could sure use some help.
I want to clean the TB too, but I'm getting some conflicting info here.
Sea Foam makes a spray (on their website)
Do you think I could spray this into the TB to clean it?
I don't want to remove the whole TB if I don't hafta...
Any help would be appreciated. Thanks in advance!