If your compression is poor, pull the exhaust pipe off and get a look up the port to see the condition of your piston and rings, if they are damaged you will know what to do.
After testing for compression and you have enough, and if you have spark, and the fuel train seems ok, and it still won't start, check your timing.
If it was an abrupt stall the flywheel could have spun and sheared the woodruff key.