I bought this about two weeks ago and it wasn't starting. I replaced the spark plug, ignition coil, fuel pump, fuel lines, starter and battery. I got it to start just about every time after that but it was running bad backfiring and wouldn't idle. I then was adjusting the throttle cable and the idle screw. After i shut it off it now will not start at all, not sure what happened. I tried to put the adjustments back to where I started and it didn't change a thing. It will crank but will not start.