After some help please. Took the carbs off bike tonight (stood for months after buying it as a non runner) On the top of the carbs there are 4 plastic diaphragm covers. Each one is held on by 2 allen screws. Each one also has a rubber cap covering a short stalk. (I'm guessing this is where you would plug balancing gauges???) Any way one of the 'stalks' is snapped off and a second has no rubber. My question is, are these supposed to be sealed? (to keep vacuum) When i bought the bike the last owner said it would not start possibly due to sucking air in?? Im hoping I've found the cause in this snapped off pipe. Second question, if this is the cause, where would i find a diaphragm cover?? Ive tried the usual, Eblag ect, but dealers seem only to want the sell the whole bank of 4 carbs. Ill post some pics when i get a chance. Thanks in advance.