If it cranks but won't start, It could be a faulty fuel shutoff solenoid on the bottom of the float bowl on the carburetor. The windings go bad in the solenoid and it shuts the fuel off, even if the 12 volt feed to it has 12 volts while key is on ! Some of them are assembled in separate pieces and you could unthread it from the carb and take out the pin, screw it back in and try it that way. But you should get a new one on Ebaky to stop possible backfiring and blowing the muffler off !! Don't throw the old on out because you might need it for parts / reference , like I did when I got one from the dealer. I used the old one to modify the new one from the dealer so the machine would start !! Lesson learned !! Good luck !! IrishJO4