Good day. I have a Dibra cutter model C-50SR. A few days ago he began to make a strange noise and does not lift speed. After removing the engine (model 8006004), and turning it by hand, I notice that a metallic friction occurs. It turns about half a turn and two metals "collide", and collide again as they continue to spin. At the bottom of the shaft, on the inner side of the case, there is a metal disk that I think is the one that causes the crash. That disk, indicated in the attached photo, when pushed with the fingers, slides about three millimeters along the axis. Can anyone explain to me what function that disc plays? Is it correct that a piece that retains it in its place is moved or broken? Thank you very much.