mackeil Posted July 16, 2010 Share Posted July 16, 2010 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 Link to comment Share on other sites More sharing options...
dtmf Posted July 16, 2010 Share Posted July 16, 2010 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 http://www.mikesxs.net/products-75.html#products Part #48-5021 and Part #48-5022 Link to comment Share on other sites More sharing options...
thags Posted July 20, 2010 Share Posted July 20, 2010 Hey Mackeil, I have a 1976 XS500C and I think I may be having some similar issues. I just cleaned the carbs out and switched to K&N pod filters instead of the stock filter, and I am experiencing erratic idling (mainly while riding) and occasional engine racing (mainly on startup, when it's still choked). When I reassembled the carburetor I replaced the gaskets, but that was it. Do you think this could be the same issue? I'd like to know how this worked out for you if you were able to get the replacements! Also, which part is the E-clip? I can't quite place it...The carbs may be different, as the bikes are different years and makes, but I'd imagine they would be pretty similar. Thanks! Link to comment Share on other sites More sharing options...
johnsnownw Posted July 20, 2010 Share Posted July 20, 2010 Hey Mackeil, I have a 1976 XS500C and I think I may be having some similar issues. I just cleaned the carbs out and switched to K&N pod filters instead of the stock filter, and I am experiencing erratic idling (mainly while riding) and occasional engine racing (mainly on startup, when it's still choked). When I reassembled the carburetor I replaced the gaskets, but that was it. Do you think this could be the same issue? I'd like to know how this worked out for you if you were able to get the replacements! Also, which part is the E-clip? I can't quite place it...The carbs may be different, as the bikes are different years and makes, but I'd imagine they would be pretty similar. Thanks! If you didn't re-jet your carbs after changing to pod filters then that is where your issues are coming from. Link to comment Share on other sites More sharing options...
thags Posted July 20, 2010 Share Posted July 20, 2010 If you didn't re-jet your carbs after changing to pod filters then that is where your issues are coming from. ok thanks, that's what I was thinking, but was unsure how the process worked... been doing some reading and think I'll be looking into re-jetting. Thanks, Link to comment Share on other sites More sharing options...
GaSo Posted July 28, 2010 Share Posted July 28, 2010 http://www.mikesxs.net/products-75.html#products Part #48-5021 and Part #48-5022 If it does turn out to be this seal, I had the same issue and documented the process here: http://www.yamahaclub.com/forums/topic/14526-1981-yamaha-xs400-special-ii-xs400h/page__view__findpost__p__79825 Link to comment Share on other sites More sharing options...
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