I think it might be the prop. I was using a 12x6 slow fly prop, so I'm going to try out a 13x6.5 and see if there is a difference. If that doesn't work, I'm going to strip down the motor and see if there is some debris or dirt inside that might have damaged a bearing or something (even though it feels fine). I'm going to try to test it out in the next day, so hopefully it'll work with this new prop. If it is the motor/esc I guess the problem will become more pronounced with the 13x6.5 prop.