3416 problems...

See if you have a spark. Also, it would be a good idea to check the key in the flywheel, since it did backfire. It may have (partially) sheared the key.

Is your gas cap sealed? Take the screw out of the base of the carb, let some gas (or water) out. Put it back in and set it at either 1 1/2 or 2 turns from seated and go from there. Next you can trace the ignition. I would clean all the contacts to begin with... Good luck!

Well I am not getting spark..... took the points cover off. Looks like its sparking to ground. Cleaned the contacts and still the same. I guess that would make sense that the flywheel key is partially sheared because the timing seems to be off right?

That would affect the timing, and perhaps prevent you from getting spark. Your condenser might have shorted, too. Do you have a spare to try in there? You might also want to pull the tin and make sure the high voltage lead isn't damaged (mice…?).

Or... I had one the mice chewed the plug wire under the shroud. It had intermittant spark. I fixed it with the liquid electrical tape...

Ok well the wires were fine. I pulled the cover and the flywheel nut. The key looked fine from inspection with the flywheel still attached. Would it have to be off to one side or all the way around. Because I see no indication that it is pushed, smushed or offset to one side or the other. Could it be the condenser? It was showing spark at the points but nothing at the plug. I know the cap keeps the points from pitting but doesn't it also intensify spark?

how do you get the flywheels off of these things anyway? I have used heat, some oil, a puller, and some taps with a hammer on the side of the flywheel and it dont want to budge. The key was loose in the hole btw... A hammer isnt going to hurt theflywheel right? as long as I dont go crazy on it.

Give it a light tap and they usually come off...

The condenser does help provide a better spark by preventing the arcing across the points. The arcing is energy lost to the coil, so a weaker (or no) spark.

Got the flywheel off. a few taps on the back side of the flywheel and it popped right off. The key was intact even though it moved in an out. I am not sure if it was the original one though as it was quite a bit smaller then what I thought it to be and it was aluminum. But anyway it doesnt look like the flywheel moved much if at all. So I guess it must have just been the condenser and I happen to have 2 bad ones.... Has a backfire ever jumped the cam or messed up a carb? Either way I wasnt getting spark. I happened to be doing the ignition switch at the same time so maybe I did short both of them out. I did test them and I got infinite resistance to the case.... but my tester isnt really for electronics I think.