These engines like a bigger prop. 1st upgrade to either prather 225, octura x447,x645,x547, or m447. Then you can start fine tuning, ie balance, strut height etc. At least that's where I would start. The stock prop is too small.

I might also invest in another flex shaft just incase the stock one doesn't make it. I ran 2 times and it broke. I grease the shaft well, but I do believe it was the strut adjustment that did it for me.