backfireing at high rpm

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backfireing at high rpm

tyrone jefferson
just got my grandpas old bike for graduation, it wasnt running smmothly past 1/4 throttle so i cleaned the carbs, but now after it gets past 6000 rpm it starts backfireing and i cant seem to get it to idle either... any suggestions?
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Re: backfireing at high rpm

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It sounds like, you have a vacuum leak. Check the rubber boots between the carbs, and the head.
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Re: backfireing at high rpm

old bob
In reply to this post by tyrone jefferson
You can run it up to 6000 then spray a small amount of carb cleaner around your boots to find the leak. also I had a ducati 916 that would back fire at high rpm's and it turned out to be a bad seat on the exhaust valve
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