This is a follow up to my "Bad Engine Knock" post dated Oct. 4th. Much thanks to emckelvy and j martin for their thoughts and suggestions. I still haven't gotten it running, but I did drain the oil, (two full quarts over!), but no water in the sump, thankfully. I also finally located a compression gauge with a 12 mm thread and ran a test. Got 115 on three of the cylinders and 118 on the fourth one. The head stays on, at least for now. Then I did a timing check. With number 1 plug removed, I can see the piston at TDC. At that time the pointer under the flywheel is right on the TDC mark, AND the "#1" on the cam pulley is right on the pointer for cyl. #1, where it should be. But, the flash of the timing light illuminates nothing! I moved the timing light around the turning flywheel and found the mark for TDC --approx. 90 or 100 degrees PAST where it should be. What has happened here? I don't think this 50 hp, 4 cyl. 4 stroke jumped timing because the piston at TDC aligns with the flywheel and cam pulley marks. Any thoughts and suggestions would be appreciated. Gotta get this running to see if there's still an engine knock to contend with.