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Main Area => General GS500 Discussion => Topic started by: kord_f on August 08, 2015, 12:41:25 PM

Title: Top end rattle
Post by: kord_f on August 08, 2015, 12:41:25 PM
I have a rattle that sounds like it is coming from my top end.  I thought it may be from the valves being out of spec but after just having them adjusted it is still there.  It is most prevalent around 4-5k rpms and mainly when accelerating.  I sometimes hear it when holding speed but never really when decelerating.  Any ides of what it could be?
Title: Re: Top end rattle
Post by: Watcher on August 09, 2015, 12:05:52 AM
Could be cam float.  Is it only when warm or at all times?
Title: Re: Top end rattle
Post by: kord_f on August 09, 2015, 08:02:57 PM
Only while moving.  Doesn't rattle if I rev in neutral.
Title: Re: Top end rattle
Post by: gsJack on August 09, 2015, 08:52:45 PM
Not cam float knock which is only when hot and only at idle and doesn't knock above 2k rpm. 

I had a vibration rattle in front maybe in instrument pod or headlight assembly or control cables at about 5k rpm under load in my 97 GS when new which I never identified and it went away after a short while and never returned.   :dunno_black:
Title: Re: Top end rattle
Post by: Watcher on August 10, 2015, 05:52:13 PM
My gas tank rattles.  Could be that.  My tank was loose and I tightened the "clamp" on the front of the tank where it attaches to the frame.  Ever since it buzzes/rattles around 5k.

Been meaning to take it off and pad it a little, but with a tank bag on the tank no longer buzzes so it's something I'll fix if the tank comes off for some other reason...

Next time you're riding and you hear it put your hand on the tank and see if it stops.
Title: Re: Top end rattle
Post by: kord_f on August 11, 2015, 11:36:41 AM
Tried putting my hand on the tank.  No dice.  I suppose it could be something harmless like Jack suggested.  Doesn't affect performance in any way so for now I'll just let it go.
Title: Re: Top end rattle
Post by: Janx101 on August 13, 2015, 03:56:37 AM
No big drama overall. .. but what SORT of rattle? ... deep and echoey,  sharp and tinny?, high pitch and vibratey? ....

Many kinds of rattle!
Title: Re: Top end rattle
Post by: kord_f on August 20, 2015, 11:53:35 PM
Definitely more vibratey than anything else.
Title: Re: Top end rattle
Post by: kord_f on August 24, 2015, 02:01:40 PM
After taking a long highway trip I have now noticed the rattle across the entire rev range.  And it appears to be getting louder.  Still only there when holding speed or accelerating but it is very consistent.
Title: Re: Top end rattle
Post by: Janx101 on August 24, 2015, 11:19:18 PM
Front sprocket bad?
Title: Re: Top end rattle
Post by: kord_f on August 25, 2015, 12:19:35 AM
Both sprockets are pretty new. Could it be associated with the carbs?  I'm fairly certain they're not synced.  Just not sure if that could cause a vibration of any sort
Title: Re: Top end rattle
Post by: kord_f on August 25, 2015, 12:23:03 AM
Both sprockets are pretty new. Could it be associated with the carbs?  I'm fairly certain they're not synced.  Just not sure if that could cause a vibration of any sort
Title: Re: Top end rattle
Post by: Atesz792 on August 25, 2015, 04:24:06 AM
Of course it could... 1 bang bigger than the other, not good for you, nor the crankshaft.
Title: Re: Top end rattle
Post by: The Buddha on August 25, 2015, 07:52:26 AM
Synch affects low rpm, past 1/4 throttle you dont feel it usually.
Cool.
Buddha.
Title: Re: Top end rattle
Post by: Watcher on August 26, 2015, 10:02:54 PM
Are you certain it's coming from the engine?

Can you tilt your head off the side of the bike while riding?  I notice when I lean off the seat in aggressive turns it does affect the perceived sound of the motorcycle.  My cams appear louder and such.

It might narrow it down left/right if anything.


Certain it's not the key?  Don't know how loud that could get, but I do know my lock cylinder is pretty worn out and my key will actually vibrate audibly at certain RPMs.  More of the kind of sound you'd expect a key vibrating to make, though.  At this point I'm just throwing ideas onto the wall and seeing what sticks...