mackeil

Hello, I have a 1980 Yamaha XS400 Special that I have owned since 1986...Lately, it has started this irractic idling and racing engine, I have narrowed it down to a vacuum leak from a shaft seal on the carburator...On each carb there is an E-clip, fibre washer and behind a small black seal which is old and dried out, the source of my vacuum leak..I went to our local Yamaha dealer to try to order replacement seals but was told that the there was no parts listing for that seal because it was a factory installed part and I would have to order an entire new carb to fix my problem...Does anyone have a more realistic solution to my vacuum leak? Is there an aftermarket seal available to fit my application? I realize I could use an O-ring in a pinch but I would rather find an actual double lipped seal that the factory used...Here is a picture link to the shaft where the leaking seal is located http://members.shaw.ca/mackeil/ Thank you, Stacey Vancouver Island, Canada