Yes its a knocking sound and i think i hear it from the left side of the motor but it is difficult to say...

Piston and barrels are new, stock bike and compression nice so i dont think

it has to do with this.

Maybe the rubbers that unite the motor with the chassis?

It does it only when riding and not on stand.In every gear, but now i

changed cluch basket it seems than in first gear doesnt do it so much like before.