Oooh baby....you are sexy!

[Tmall]

Originally Posted by shmike

It is not a flat spot, it's a trench. I could easily feel it before a pipe and remap.

I agree that it doesn't taper off at the end. Very easy to hit the limiter if you aren't paying attention.

What I find odd is that you're describing the flat spot basically right where the exhaust valve shifts positions. I could definitely feel the flow path change over, but would never have called it a flat spot.

Now that I have the way too loud pipe on it, no more "stutter" when the valve shifts.

Depending on the bike, the cable could have been loose for the valve, or the muffler could have been dented in a spot that would have compromised the smoothness of the valve movement.