Rugging with fast power query – Zündbox?

Hello, I’ve noticed since the day before yesterday that my 97’s 2.0lpt is jerking with fast full-gas (turning out, so to speak) when I slowly question the performance it behaves quite normal. The stand-up gas is also normal, I give in the stand fast gas, so nothing happens, so only under full-stitch it jerks, and such a noise a bit like a broken exhaust… . Now I’m close to the guess with the ignition box, have read here also that the thing holds so about 100tkm, I have now 116tkm… . Am I on the trail of the mistake? Other ideas? If this is the box, where do I get the (best new) favorable, what is the so cost, and should I immediately exchange the spark plugs (which are the best)? In short, I thought that it might be this black cylinder-shaped thing, that on the vertical pipe, that goes on air filter tube, that must be opened/close at the power call too quickly, or can it be just the sparker?