I was recently tuning my 4 stroke lawn mower to shoot flames. I messed around with the intake valve, and soon found big flames coming out my exhaust. How ever the next day there was no compression and it won't start.

What is my issue? Also it may have been over filled with oil how ever I fixed this quite quickly.

  • 2
    Welcome to Motor Vehicle Maintenance & Repair! How were you adjusting (what method) the intake valve? (A better question yet is why?). Also, what kind of engine is this (get as detailed as you can)? Sep 19, 2018 at 22:57
  • I know it is a 4 stroke, overhead valve motor. 1.75HP?? Maybe different HP.
    – Doobs
    Sep 21, 2018 at 6:19
  • It would be helpful to know what the reason for adjusting your intake valve was. What issue were you hoping to resolve? If it was adjusted hot but set to it's cold setting, you may need to reset the adjustment now that it's stone cold. Dec 19, 2018 at 10:10

1 Answer 1


You should reset the valve timing back to the original (you did make a note of the relative marks before changing things).

Then you should check that the engine turns over with no binding / interference and then check you have compression.

Hopefully then it will start.

  • Do you have snapchat or facebook?
    – Doobs
    Sep 21, 2018 at 6:18

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