Ok finally got to fly my 4-star 64 with the YS 115. Turning a APC 17/4 wide blade and it is a perfect combo. This motor has got some grunt I ran 2 tanks of fuel on the ground and then flew. I need to get my tach batt replaced but it rips the prop at 3/4 throttle. This motor runs like most 180 size 4 strokes. Very easy to adjust mixtures and you have to fool with the regulator that is what I love about it. Going back out today and try a Xoar 17/6 wood prop just for kicks. I had to add around 6 ozs of tail weight and still could use a few more on inverted fight still has a little nose heavy feeling but not bad. Very pleased so far .