Help with my freeflight helicopter

Hi Cox fans
Lately i have been having a problem with my free flight helicopter.....when i run the engine in my hands as the blades rotate , i burn all the fuel..however, when i start the engine run it rich ,then back it up for lean as cox recommended when they were around
it flies up then it cuts out.i replaced reed valves ect. the problem does't go away....does anybody know what the problem is?

Thank you
Body123

Sounds normal to me. Intended small fuel tank, short duration. If they run to long they can get away from you.

Which Cox is it? Orange Sky Copter or some other?