S2R1K Not sounding right

[Kabulpostie]

So, as the title says my '06 S2R is sounding different...not sure if it's my imagination, but the exauhst note seems off. and when rolling off the throttle it seems like I get some "stutter" before I roll back on..The change in sound is almost like it sound buzzy. The only thing I have touched that may have affected things is I tried to wipe out the velocity tubes (I think that's right, the funnel shaped things in the air box). I did that after reading a thread here that indicated build up by the valve that opens up to let air in when you twist the throttle (sorry it's early morning and I can not for the life of me make my brain function) may help the occasionally uneven idle issue. Anyway is it possible that while I was trying to reach down to wipe stuff out that damaged/moved something that would make the bike sound funny?
I know this highly detailed and technical report ( ) may be hard to follow, but I appreciate any effort to help .

[Slide Panda]

It's highly unlikely that running some rags around the velocity stacks did anything bad.

But, your stutter comment makes me wonder - What sort of condition is your chain in? Is it properly tensioned? If a chain is too lose it can slap and clatter against the swing arm. Also an over slack chain can give you a feeling of 'lash'. If you're on the gas, the top of the chain is tight, if you coast not the top is slack and bottom is tight - if you get on the gas again, all that slack needs to be wound up again which will give a feeling of lag and stutter

[stopintime]

.......
The only thing I have touched that may have affected things is I tried to wipe out the velocity tubes (I think that's right, the funnel shaped things in the air box). I did that after reading a thread here that indicated build up by the valve that opens up to let air in when you twist the throttle (sorry it's early morning and I can not for the life of me make my brain function) may help the occasionally uneven idle issue.

http://www.ducatimonsterforum.org/index.php?topic=66058.msg1219588#msg1219588

Besides Slide Panda's chain advice, check that the parts you removed/touched are put back together correctly (airbox and filter tight?)

[DucDucGoos]

When was the last time you did a tune up ?

[Kabulpostie]

Hmm, Thinking tune up might be something to look into. I had the valves, oil, brake and clutch fluids changed/checked about five hundred miles ago, but nothing else..is there something specific I should look into?

[Slide Panda]

What did they do for the valves? Check the clearances and adjust if needed?

[Kabulpostie]

Exactly

[Slide Panda]

Hmmm. So just speculations/questions presently.

- Did they sync the throttle bodies?
- It's not acted funny until recently? IE, it was fine for a few hundred miles, then started acting up vs acting up as soon as you rode it after the shop time.

I still doubt your time in the airbox did anything. There's nothing really that you can cause harm by, unless you somehow dropped something hard, like a bolt, down the intake.

Other random speculation - bad gas. It does happen from time to time that you'll get some junk gas which causes crappy running

[Kabulpostie]

They didn't do anything else, not their fault, I specifically asked them to only check the valves and change the fluids. We did change spark plugs as well. It has been about 8,000 miles since the last full service. There may be an element of mechanical hypochondria, but I don't think so.

[Slide Panda]

Again, I'm just flailing a bit here but

- TBs do lose sync over time
- What did they say about the valves? Anything get adjusted?

[Kabulpostie]

I don't remember the exact wording on my receipt, but I believe it was something along the lines of " Number two exhaust grossly out, adjusted to spec"  may have that wrong, basically one valve was out and was adjusted.
I haven't noticed any performance change on my butt dynometer, it's just sound, maybe I'm nuts...

[Slide Panda]

Well if an exhaust valve was way out of whack it's possible that getting it to rights would change the sound. If it wasn't closing or opening all the way it would effect the note.

Now the stuttering you reference... that I'm struggling with.

[Kabulpostie]

I wasn't clear on the stuttering..it is a sound from the exahst when I roll off the throttle...like gas is still being burned...guess on my part

[Slide Panda]

Is it a popping? Usually a couple distinct noises?

[Kabulpostie]

Yes! Different than the cool sounding burbling, farting sound when you downshift and slow though.