Re: 156 Selespeed Hi Revs
What did you do to clean the throttle?
The elctronic throttle on thge Selespeed is very tempramental and is very easily damaged. I've only ever cleaned mine by taking the rubber hose up to the butterfly off and spraying it with carb cleaner. That seems to help running. Have a look at it when the engine is off. It should be closed completely with a tiny bit of play in the throttle butterfly away from its stop. If it is open a little or flapping it is sick.
Sorry I can't be of more help.