Run well or run quite?

[Scotty426]

Anyone hear any theories about why older (up '03) Yamahas don't run well when quiet? I had trouble when I put in a quite core insert. I tried every jet combination known to man and it cleared right up when I took the insert out. I have read about this phenomena in a few magazines, but they never explain why.

[yamahauler44]

im not sure why, but thanks for trying to keep your bike quite! that = more areas open.

[Guest RIDE_for_RED]

race bikes were made for track in mind. not quite puppys. mess /w/ the jetting more, go down 3-5 #'s on every jet. (needle, 1 clip)