On a small rotary mower engine like this one, the flywheel is at the top of the crankshaft and held into place by a soft metal key which is designed to shear if the mower blade hits an object. The flywheel itself is almost impossible to damage unless you drop it once it is removed from the crankshaft. Timing is spot on with the new key I installed although it was a few degrees off when the key sheared originally. I am going to swap out the magneto with the one on my newer Yard Man pusher to see if that makes any difference. As for starting fluid...rather hard to spray it into the carb intake while pulling the starter rope and holding the handle at the same time. I could probably pull the plug and squirt some in and reinstall the plug and try that...still, seems to me if this mower wanted to start it would at least fire once in a while but it won't even pop once.