I wish it was as easy as pushing a reset button.
Im not sure is this a 2 or a 4 stroke.
If its a 2 stroke, air may have got in to the oil injector line, causing oil starvation. leading to a blown motor.
Or the impact may have caused the timing to jump out of whack, Check your cam gear position etc..
Did you put in a new spark plug, the plug may be soaked in oil and gas.