There were some differences in the Bing CV enricher operation over the years. Early ones like my 79 flat tops originally had only one fuel hole in the disc which explains why it's all or nothing in operation. I don't know when they changed but later models have several fuel holes of varying size to provide a progressive action.
There was service bulletin S1300179 100R issued in Jan 79 for the R45/65's with flat top Bings. It describes modifying the disc by enlarging each of the 4 drilled recesses to 2.5mm and drilling a 0.6mm hole in the 4th position. The bulletin also states that spare parts are already modified and any carbs updated by the dealer will have a spot of red paint on the enricher housing.
Next time I have the carbs of I'm going to give this a try.
Ticklers if they could have left out the mess was a brilliantly simple automatic choke that provided enrichment that diminished as the fuel level fell. SU did it much better by lowering the needle jet to achieve the same result.
190e screwed with this post 07-27-2013 at 12:07 PM