If yuo pull the plug and crank the engine with an electric starter... cover the head with a rag. The engine can spray fuel several feet... and that can blow the fuel directly into your eyes. THAT can be VERY painful, and there is a chance of it permanently damagng your eyes.

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Without actually seeing the engine and hand turning it myself... its nearly impssible to diagnose it from the description.

My first guess would be you burned out the glow plug and it dropped the fillament out into the cylinder... and tat is starting to gouge the cylinder liner. If that is what is going on... STOP TURNING THE ENGINE! or you will destroy it. (might have already done severe damage...)

Find someone with experence dealing with glow engines to IN PERSON look at it. There is no other way to deal with this one.