Have had my China Roller 125 (Znen) today at the tuv. As far as so good. When I drove then 60 km a little harder (almost full load) and everything was quite hot, he did not accept gas, only when I let go of the gas and again gas Gab, went. On the return trip it was similar that he shrugged and briefly bad gas took on. Cold and medium warm it was not a topic. Does anyone have an explanation? spark plug new, forgot cleaned, nozzles clean, gasoline filter new, new belts, fresh r Fuel .