While my MMM combo is in for repair I picked up a speed passion silver arrow II 9.5 motor to run with my mmpro in my mp9e. It seemed fine with the wheels off the ground but when I actually tried to take off it just stuttered and cogged horribly. I tried sensored, sensorless, and smart sense modes and it seemed to make no difference. I also added a capacitor to the rx which might have helped some. I messed with the settings and managed to get it to take off mostly ok with high start power, and timing set to like 20. Now the only time it does it is at full throttle under higher loads, like a hard high traction launch. The problem is the stuttering continues until I totally let off the throttle and smoothly re-engage it, and I'm worried about heat issues running the timing so high. I tried firmware 1.26 and 1.29 and it seemed the same.

Anyone have any ideas what might be causing this? Does it sound like a motor or esc problem?