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Main Area => General GS500 Discussion => Topic started by: lumpoffire on January 30, 2004, 07:54:10 AM

Title: Revs fall slowly when warm; Vacuum leak?
Post by: lumpoffire on January 30, 2004, 07:54:10 AM
Sorry if this has already been covered.  My '91 does this.  Can anyone tell me if this condition is a symptom of leaking vacuum?  Also, the bike sounds kind of "rough" and perhaps a bit louder than I'd expect a stock GS to be, though this is the only one I've ever ridden.  

Thanks for any suggestions!
Dan
Title: Re: Revs fall slowly when warm; Vacuum leak?
Post by: gsJack on January 30, 2004, 08:42:10 AM
Quote from: lumpoffireSorry if this has already been covered.  My '91 does this.  Can anyone tell me if this condition is a symptom of leaking vacuum?  Also, the bike sounds kind of "rough" and perhaps a bit louder than I'd expect a stock GS to be, though this is the only one I've ever ridden.  

Thanks for any suggestions!
Dan


That's common when the idle speed is set a bit high.  After completely warmed, turn the idle adjustment knob under the carbs out a bit till it doesn't hang up anymore.  I can reach under the carbs and adjust it while sitting in the bike.  Works best with gloves on with a warm bike.   :lol:

If this doesn't fix it, then you might have another problem.  Folks tend to set the idle too high when adjusting w/o completely warming the engine.  If the engine runs poorly when the bike is cold and smoothly when warmed up, there could be a tight valve.  Time to check valve clearences.