A resonator port helps increase the exhaust port volume which builds bottom end.
The problem is, it kills off some of the top end.
So a resonator port needs to be able to be opened and closed.
Kawasaki did just that through the use of their KIPS valves.
Here is how.
Here is a pic of the opposite side.
The carbon shows where the port is
![Shocked :shock:](./images/smilies/icon_eek.gif)