FX impact power wheel binding/stuck

It sounds like you tried to adjust the power wheel when the gun was cocked. Was this the case? If so, I think you can adjust it back, so long as it is no longer cocked.

The reason you can not adjust it to a higher setting while it is cocked is because you are trying to rotate that wheel against the spring tension (actually, it is a bit more complicated than that. But, I don't want to type all of that :)). It is possible to adjust down while cocked because you are lowering the spring tension. But, this still is not ideal. Better to always make adjustments with no tension on the spring (ie. uncocked).