so i finally got around to opening up the head of my lawn mower and found out why it wasnt running.

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the intake push rod is bent. and the exhaust is straight. obviously my valves were way out of spec and needed to be adjusted but that ship has sailed. could the intake valve also be bent? when i push in on the intake valve there is no sticking and it moves smoothly. also would there be any damage to the piston face if the valve came into contact with it?


  • 2
    Welcome to Motor Vehicle Maintenance & Repair! I'd suggest if you want to know if there was any damage to the valve without taking the head off is to pressurize the cylinder and see if it leaks. If the intake valve is bent, you should be able to hear the air escaping through the intake manifold. Also, what kind of lawn mower engine is this? Feb 8, 2019 at 20:52
  • 31P677-0140-B1 that is the exact engine number. is a 19.5 hp briggs and straton engine out of a john deere riding lawn mower. the mower has about 240 hr's on it. so it is pretty old. and thanks for the response. i will try that.
    – CJC
    Feb 8, 2019 at 21:04
  • i have since replaced the intake push rod. as well as put the valve clearances to spec. the engine runs fine so i am guessing there was no damage!
    – CJC
    Feb 20, 2019 at 21:03


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