Am cleaning/rebuilding the Keihins on my 1977 750A and have a question regarding the tiny metal washers on the pilot air jets.
When I dismantled the carbs, one metal washer was missing. I have a spare (old) set of carbs, but there no metal washers on the pilot air jets. First question is ...are the metal washers essential ? Second question, if they are, what do they do ? Looking at the schematic, it seems that the arrangement of rubber o-ring and metal washer is wrong, first because if the metal washer goes on last it falls into the jet tube when the carbs are on the bench float bowl up, and second because the spring then acts directly on the rubber o-ring. I would have thought the metal washer, if it does anything, would act as a "mini thrust washer" for the spring. Any info greatfully received.