Stuttering @ higher RPM

[MTYooper51]

Today while riding over my lunch break my bike began stuttering at 4500 rpm while in 3rd gear, I downshifted to second and it did not happen. I changed the plugs and both oils this past weekend. Any ideas? The bike is completely stock and just barely over a year old. I've also noticed a slight "knock" coming from the bottom end/transmission area ... could these two be related? Thanks.

 

[dave_xb12r]

Did you gap your plugs?

 

[MTYooper51]

Yes, according the the sevice manual.

 

[Stevenc150]

Have you:

- Checked the play in your Primary Chain? ("Buell Service Manuals" link at top of page if you don't already have it.)

- done the Breather Reroute Mod? - Just a standard mod that helps with lower end stuttering.

 

[MTYooper51]

I am thinking of doing the breather reroute mod soon, since i have noticed some lower end stuttering as well. Is there anything I need to do ECM-wise though after doing the reroute mod?

 

[Stevenc150]

No, it doesn't affect airflow enough to merit even a TPS Reset. You're good to go after the mod.

 

[chase12s]

I didn't even notice much difference after the breather mod. Guess its a little smoother off idle.

 

[MTYooper51]

So i'm thinking it may be a loose primary chain thats causing the "knock." I know that the play in the chain can be checked in the little side window but does anyone know of a good way to check the deflection accurately? It's really hard to measure 1/4-3/8" through the inspection point.