Bought a used 2016 850 high lifter ran it 100 miles started knocking brought to dealer … They say this ATV has been here and it was swamped all we did was a oil change … Now motor is needs to come out I’m going to do it myself and a good friend of mine who builds engines I can’t spend 4 k for a new one ! Already have to much into it now. Where have you guys got complete rebuild kits and looking for recommendations for upgrades pistons maybe or a cam . I dont want to do any to crazy to take away from reliably. Thank you