After more than 40 years the O-ring between the petcock and the fueltank is sweating. That ring is obtainable in the complete strainer set 16952-341-671 for my type petcock that has the nylon filter protruding into the tank. But I don't need the filter nor the nut nor the rubber piece with two holes (all still good), just that O-ring (shown in the middle in the pic below). Does any of you happen to know what size it is? There's a shop in town that does all kinds of O-rings. I could take the old one there, but there's little chance my ring still has its original size after all the different gasolines it has seen. Hence my question. Thanks in advance.