power valve springs

[Livefastdiefun]

i herd about diffrent power valve springs to change how your powerband hits... im just wondering if anyone tried them yet and how they worked
thanks.
-jake

[Racer38]

I have the Red spring in my 2004 250 EXC, I also have the 250 SX head and piston. The bike Hauls butt and the red spring with the adjustment set flush allows the PV to open easier, has a nice hit to it which is what I am use to riding.