earlier today my 422 power-trac the carburetor started popping, it then stalled out, i removed the valve cover the push rod was off the rocker i put it back on and tried to adjust, but the tap it became stuck, I freed the tap it up, and the tractor worked, i then adjusted the valve, but when i backed out of the garage the next day it stalled out when i put the PTO in now it will not start at all, the battery is fine, i have voltage to the starter but i think it might be the ignition switch do you think i'm on the right track?, any help comments or suggestions will be greatly appreciated.