I thought I'd share with you what I found with my friends 2011 EC125. The bike had no bottom end power at all but tons of top end power. We figured it the was the power valve being stuck open becuase it was gummed up. It turned out to be the spring which slid out of place. See the link to the video on youtube. I swapped a bunch of powervalve components with a YZ125 power valve. The components had slightly different shape to the springs and center actuator which bolts to the shaft but nothing completely fixed the problem. I ended up just cutting one of the bushings from the YZ125 donor bike and adding it on the shaft. (It is on the far left side of the shaft shown in the picture)
https://www.youtube.com/watch?v=fFI3NhqU61s
Hope this helps others.
https://www.youtube.com/watch?v=fFI3NhqU61s
Hope this helps others.
