Ok I do need help again.

I adjusted the engine, it ran good for the first two flights then after a while it started to run erratically after mid throttle. It started to malfunction at the top of rpms and then all the way down to mid range. It ran good until mid throttle is achieved, after mid throttle, it can not pick up rpms. No matter what I did to the H screw (richer- leaner), it is the same, does not matter. After a short break, the engine was marginally better, just to fall again under the same situation. So the heat is in the equation, but It did run good idle to mid throttle ?. The spark plug is OK, the ignition is working at least from idle to midrange, but I can not run it after that. Any ideas?
I adjusted the H screw reaching first a peak, then I back it a little, dropping some rpms (200).
The L screw is lean, but not so much.