I've finished the job. Same result. The engine works well at medium speed. 8900 rpm and 120°C or 255°F. I used 12x6 (not good), 11x6 and 10X6 propellers. Same situation. When the throttle is coming up, the engine dies. I made a lot of combinations with the low and high valves. .
The tank's level is correct and it has pressure.. I give up for today . Maybe next week I'll try again. Thanks all for your help.