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Engine kicks back when starting
 

Kick back occurs when the timing of the ignition system fires too early during the compression stroke. When the air and fuel mixture ignites, it forces the piston back down the cylinder bore in the opposite direction of rotation at a tremendous speed.

Be careful...the engine can kick back hard enough to break an arm!



Common Causes:
 
  • Check for a sheared or partially sheared flywheel key. Replace it if it's even slightly damaged.
  • If the flywheel key is not damaged and your engine is the type that has a manual timing adjustment, the problem may be due to advanced ignition timing.
  • If the flywheel key is not damaged and the engine size is 5 H.P or larger, check for a malfunctioning compression release. (If the engine is equipped with one.)
  • If none of the options above resolve the problem, you'll need to check for damaged or mis-adjusted timing gears.