hi i have an 89 kmx 125 recently bought was told power valve not working something to do with the arm? doesnt seem to kick in. do you think this will be expensive to repair many thanks

craigwolf, January 2007

well that engine uses some small gear driven shafts to twist two powervalves you need to see if they twist when the throttle is opened ie revved up,if they dont move then i expect the problem will be with the small gears or the powervalve governor in the front rh side of the engine .take the caps of the side of the barrel to see if they move when its revved up ok.

adam bike doctor, January 2007

it has a kx 125 engine in it

craigwolf, January 2007