I had just gotten a 2001 CBR 929rr, and its rides great, but one thing ive noticed is that when it idles, it slightly idles up and down. it doesnt idle up high, but you can definately see and hear a slight up and down idle. And being that these newer bikes are fuel injection, what would cause that issue? and what would be best for me to do to solve that issue? Other than that it runs great, and the fan clicks on around 205f to 210f, so i assume thats fine also..I hope ya'll can help with that idle issue?? Thanx

 

It not really an issue. its just your idle is set at an rpm that allows this to happen. Just raise or lower your rpms by 100-200rpms or so and it should clear right up.

what happens as the gas trys to escape, at certain rpms,exhaust pulses are not pulled out by the other pulses as effectively, so you get a lopey ilde. If you slowly increase your rpm with the bike in neutral, you will notice that it smooths out, then gets rough, smooths out, then gets rough. It keeps happening throughout the rpms range. the bikes rely a lot on the tuning of the exhaust to scavange and actually help pull the next pulse along with it. the difference being that you really dont notice it while your under power, but you can hear it if you listen for it. Im sure there is a more technical way of putting it, but thats the basics of whats happening.

 

Thanks for posting this question Lastchance; my bike does the same thing and I didn't know if it was something defective to possibly be concerned about (FPR).

Justasquid ~ you the man