You simply said "evo trainer system" that is not enough info to me. What is the displacement? .40, .46 ?

Your current prop is good for stirring paint. Depending on your displacement and airframe type you choose a prop. 10x5 for a .40, 11x5 for a .46. Master airscew for surviving ground strikes or APC for performance.

The low end is also over controlled by stops that sometimes must be adjusted. I also use the pinch test for the low end only I count seconds after I pinch looking for the engine to die at "seven" seconds. less is lean, more is rich. Adjust accordingly.