Güldner AX8 turns high uncontrollably

Hello, a nice shock to the evening was that earlier… I just wanted to let our old Güldner warm up for oil change. Turns however uncontrolled high. The suffering then somehow ended after I could grasp some clear thoughts after feeling shock-rigid again.https://www.youtube.com/watch?v=1sst8AQYcMc What can be the reason for this? Engine type Güldner LX 0.6l 1 cylinder 11PS Bosch injection pump, type: PFR 1 K 70/76/7 The previous day he ran still completely norma l, I had just been to the Dekra to renew the HU that had already expired in 2017. Then I tried it again with my grandpa and directly armed to take the air away from him. At the next attempt directly again uncontrollable turn up (so keep on the tip between and rather run away and wait). And the realization, no matter how good one holds, he does not go out. However, the haunting was again suddenly over again. We then agreed on it tomorrow further z But my grandpa couldn’t let it go. In short. Now he’s back to normal as if he never was anything. Now I don’t think you have to discuss that this can’t happen again (!). Especially since the second time acoustically already a speed range was clearly above full throttle and the engine can certainly destroy much faster by breaking off the conrod or something similar than one is nice. Where would you like to start with the search? Possible without an uncalculable Is it possible to take a risk?