If your RC model is stalling while opening throttle than your engine is running too rich. Too much fuel is getting into the carburetor for the amount of air. Turn the high speed needle(the one in the brass tube ) clockwise about 1/8 turn and test. Repeat as needed until

the engine has good throttle response and doesn’t die when the throttle is opened quickly. See the engine tuning instructions in your manual on how to set the low-speed needle and youtube videos