Help. I have had this Stihl 084 for 15+ years. Installed new Stihl piston and cylinder about a dozen years ago. Ran very well. In 2011, it stopped firing. Installed new flywheel (1124 400 1200), new coil (2 204 222 114) and new trigger (1118 400 1001). Saw performed really well until recently - started kicking back when cranking. Reset coil air gap to .008 - no improvement. With each rope pull, kick back occurs first time piston nears tdc. Kick back is very violent - just broke second rope. Firing shuts decompression valve, unable to apply enough force to hold decompression valve open. Woodruff key, crank and flywheel appear perfect .
Any ideas re cause and fix?
Any ideas re cause and fix?