By the time you purchase an impact tool you should look for a replacement engine.  Two years ago I picked up a Honda mower for $20 that had an issue with the valves.  I was going to break it down and repair it until I came across a new Honda engine on eBay that I purchased for $104USD delivered.  Way cheaper than buying tools and an easy fix.
	
		
			
		
		
	
			
			 
				 
 
		 
			 
			 
			