Small Engines (Lawn Mowers, etc.): honda gx 240, bed edger, valve clearance

Question
Thanks for any help.
GX240-242 #GC04 4122476

engine installed on bed edger starts fine idles fine
when you throttle up it backfires and sputters and causes the manual choke lever to shut on carb.
fuel mix /valves??

Answer
jp

If your Engine backfires the Possible causes:

  1. Carburetor set too lean.
  2. Magneto is not timed correctly.
  3. Valves are sticking.

Check the carburetor and make sure that the magneto hasn't moved ay all look at the flywheel keyway.Check the valve clearance