Tom is absolutely right Eric,
And I will add something else based on some things you mentioned
(1) if when releasing the clutch the engine has enough compression to almost pitch you over the bars, then I would say the compression is fine.
(2) Based on the video you listed, I can tell you that the amount of rotation you are getting with the flywheel/mag. Rotor is to much I've had the flywheel off 2 of my engines and neither of them were like that, best I remember they had very little to zero movement when seated on the crank, that is a problem with either the key or one of the keyways, Now if the nut is tightened down very good while the flywheel is in the proper position it should be fine as long as it fits tight on the crank but yours doesn't, so IMO that is a definite problem that needs to be addressed.
(3) ?.... After a good pull behind the mower have you imediately pulled the plug to see if it has any signs that the engine is actually getting fuel?
You said you have a strong BLUE spark so if that is the case and the timing isn't a mile off that engine should be busting off and trying to run.
In my honest opinion here, you have a very simple problem with this engine that you are missing, and like I brought up origninally in this series of posts.... CORRECT TIMING is essential IF all else is correct.....
IF you do have fuel, compression, spark then timing is still likely your problem and like I said you for curtain have an issue with the play in the flywheel.....that isn't normal on ANY engine....period, that rotor is the link that controls the spark timing in relation to the position of the piston to a great degree, if that engine is firing way too soon or way too late it will not run, and the occational pop you are hearing is just built up fuel vapor being set off by the spark plug at the wrong time.
Fix that lose flywheel issue and make sure you are actually getting the proper amount of fuel through the carb.
I made a new woodruf key for one of my engines by cutting a piece from a flat steel washer with my dremel tool that already has that radius on the edge, tyhat was 400 miles ago on that engine and it's still going strong.
Dont quit on a perfectly good engine most likely, this is a set up & adjustment problem and that engine will run IMHO.
Peace
Eric,
If you're able to rotate the rotor (magnet) on the crankshaft, there's a problem. The woodruff key and the key ways should keep that rotor stationary. You should not be able to move it back and forth. Are you certain the key is in there? If so, check the keyway in the shaft and the rotor. One or the other might be cut too wide. Advancing and retarding the ignition too far could be your problem.
Tom
