I have been reading the posts for this topic and have followed all of the advice. I have replaced spark plug, solenoid, ignition coil,fuel filter, and verified fuel solenoid is working and I have spark. But my tractor still won't start. I have tried some starting fluid and will get an intermittent pop on occasion.
I was reading in my owners manual that the valves could be out of adjustment.
I have used my tractor at least a dozen times already this year. I was mowing the other day and it just quit.
Any Ideas?

More likely the flywheel key is sheared. The key is located on the top of the engine where the flywheel mounts to the crankshaft.

Thanks for your input. I just went out and pulled off the flywheel and the flywheel key is still in good shape. Any other ideas that may leap out?
Marbury

Remove the valve cover and inspect the valves.

Thanks for your advice. I am currently out of town for the next week so I can't pull the valve cover until I get back.

remove the valve cover and inspect the valves.
I just removed the valve cover and discovered that the rocker arm on the intake valve had slid off. I loosened the nut in the center of the rocker arm and put it back over the intake valve and snugged up the nut on the rocker arm. Is there something else I should do to this? Could there be something that caused this to happen that I need to be aware of? Is there something I need to replace instead of what I just did?
Thanks for your help

Well I put it all back together and it started up and seems to be running fine. My son is out there now doing laps around the yard.
Thanks mowerman.

Sorry to be so long getting back to you. To properly set the valves, you do:
1. run engine for 5 minutes
2. remove spark plug, (the following steps have to be completed on each cylinder).
3. remove valve cover.
4. get piston to TDC and 1/4 INCH past TDC.
5. using a torque driver and wrench, adjust the valves to .005" (I believe is correct on your engine).
6. If you have more than one cylinder, be sure to complete on both cylinders and make sure you are 1/4 INCH past TDC.



EVEN THOUGH IT IS RUNNING, YOU MAY BE LUCKY, BUT I WOULD TEAR INTO IT AND SET THE VALVES CORRECTLY.