We'll here I go again thinking my 235' is just running so good when all of a sudden, my vacuum advance just is not operating. I'm holding around 17 hg's from the line off the carb., but from idle up to about 2500 rpm's the lever is not moving what so ever, the engine want's to stumble a bit to.Could this just be a bad unit or is there something internally wrong in the distributer? :confused: