Got a jd l100 5 speed with the 17.5hp briggs, won't start and backfires through the intake with the carb off, keyway was fine so I pulled the cover off to find a bent intake pushrod and broken rocker adjusters. I believe the valve guide is in its proper place so I'm at a loss as to what happened. Any advice would be appreciated 

	
		
			
		
		
	
			
			

 
				