Vibrating my nads off...

[vtlion]

My 97 GS engine (10k miles) has been making some strange ticking and clanking noises lately.  I suspect the cam-chain tensioner is the culprit.  I don't think my latest little quirk is related, but since I'm not so great with engines I thought I would include that little tidbit.

Lately at 5000rpm (and only at 5000rpm) my bike gets loud as hell and vibrates like I'm breaking the sound barrier or something.  It took me about 10 minutes to get feeling back in my two best friends (and I don't mean the ones in the Winnebago :lol: ) this morning after riding in to the lab.  It feels/sounds fine at 4500and below.... same for 6000 and above.  It only happens in the 5k sweet spot where I normally cruise.  If it were this loud at all rpm's I would be checking to see if my exhaust fell off   .  I recently tightened the header bolts on the exhaust while troubleshooting a different problem, so i'm fairly certain that its not that.  Does this sound like a normal exhaust problem?  I'm really confused by the rmp-dependance of the noise and vibrations.

Any ideas?

[dmp221]

Sitting on the bike in neutral, can you bring the engine to 5000 rpm and duplicate the sound?

[vtlion]

ah.. good question.

I gave it a gun last night in the driveway and still heard/felt it, but I can't recall if I was in Neutral or just clutched in 1st gear.  I'll have to give it a try this evening when I get home.  In the meantime... if I understand what you're getting at, I'm fairly certain that its not related to the tranny or clutch.  I can say for certain that it happens in all gears from 1-4 because that's usually as high as I go around town and I feel it whenever I hit 5k.

[vtlion]

After riding home tonight I gave it some gas in the driveway in neutral.  I'm pretty sure it's still louder than normal, but its more pronounced when I'm out on the road.  does anybody have any ideas?

[miket]

Carbs out of balance can do that. Do a search, there are several threads on the topic.

[yamahonkawazuki]

mine gets louder when it gets to happy-land , (5k or so, but vibration is almost non-existant, now with the exhaust (factory)drilled, it is loud, and in happy-land annoys the hell out of the neighbors  

[goat]

I realize this is an older post, but what did you end up doing to fix your bike? Did you figure out what was going on?

[vtlion]

I never did figure it out.  The bike ran fine.  I sold it to ChrisDC a few months ago.  I told him if it bothered him that he should start with the bushings under the tank, but I never heard back  :dunno: .  The rev-range implicates the tank.  There is a well known resonance around 5krpm.

maybe if ChrisDC is eavesdropping he can give us an update on it.

[BRB96Z34]

Was the noise a howling type of sound?  Mine does that right at 5k.  Starting to drive me nuts.