I have Cb500w 98 model here in the UK and its been back firing alot and not firing up. Sure enough on taking the carbs off and inspecting the rubber membrane diaphragms are both holed. The rubber membranes are cheap to buy but I can't seem to remove them, on parts diagrams there listed as a complete assembly (honda part number 16111MY 600). Yet u can buy the exact same membrane on ebay without the body. Yet I can't seem to get them off don't really want to have to pay for another set of bodies as there expensive. Anyone had any experience with these on removing or replacing them??