This is the way to change the prop. Change the prop driver to a small one. part # EVO100219. Any two bladed spinner. I like a APC 10x7. Next remove the baffler from the muffler, and watch the power increase. You will also have to retune both needles. On the low end loosen the small set screw and adjust the low end with a srew driver, when you have it set tighten back the set screw. then reset the the high end. This wiill increase you tapend about 20
20mph. Dennis