The issue you are experiencing is generally a timing problem. Some of the possible problems could be - 1) Bad CDI box 2) A slipped flywheel because of broken locating key "woodruf key" in the engine crank system. Which will throw your hole timing set off and as you stated the bikes engine will actually run backwards due to the badly miss timed engine. Edit - @MichaelDonald Of course I'm glad I could be of service! I would recommend bringing the machine to a specialist and have them look it over to figure out what the issue is.
Thank you so much. I know this machine has no timing chain or belt. I took off the stator cover and looked for marks for top dead center but there was nothing.
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