Craftsman riding mower backfires, won't start

[Ifixdit]

OK,think I found the answer. The exhaust valve clearance had a huge gap in it when I looked. I was reading that this can be caused by overheating, which causes the valve seat to come loose and get caught under the valve. It is commonly caused by a mouse nest built around the cylinder cooling fins. I did have a lot of mouse nest debris on the cylinder. This would explain the lack of compression and the large gap. Now I hope I didn't bend a push rod when I reset the valve clearance while the seat was still under the valve. Planning to pull head next. Could use some info on how to remove head, seat the valve seat and put it all back together.

To pull the head you will need to do several things. The shroud needs to come off. The muffler will need to be removed. On alot of mowers there is also a heatshield around the muffler that will also need to come off. The carb will need to come off. Remove the magneto. You'll need to remove the valve cover and loosen up the rocker arms and remove the push rods. The steel rod is exhaust and the aluminum one is for the intake. Once they are off all you'll need to do is remove the head bolts and the head wil come off. Check the head gasket and replace it if it is damaged. The common method for setting the gap on the valves is to bring the pistion to TDC on the compression stroke. At this point, both valves will be closed without any pressure on them. In lieu of a manual I normally set my valves at .005 each. Hope this helps.