Hi,

I have a mid engine rider with a 30 inch deck, and a 11HP Briggs engine. I mowed with it yesterday, and as I was coming into the garage, I idled it down, and it backfired and died, and would not start. Today, I checked out the following;

Check fuel
Checked for fire, both good.
Checked fuel filter
Cleaned out carbarator thourghly, (2 times)
Removed spark plug and checked spark at cylinder end.
Checked (and replaced) shear key thinking it may have gotten out of time, good, but I still replaced it.
Drained and replaced gas
poured small amount of gas in the piston

I was able to get it to fire a couple of times, but with very little success.

So, heres where it gets crazy. I can remove the plug wire, and put a screw driver into the boot and let the shaft of the driver arc across to the plug, (about an inch down the shaft from the boot, and then turn it over and it starts and runs fine!!!! If I plug the plug wire into the boot, then it will not start. My next thing to try is a new plug, but have not been able to go get one yet. Does anyone have any idea what is going on? is it the plug, is it out of time, or am I going crazy?, (please don't answer that one) I've never encountered this before!

May just be a bad spark plug boot. Try running it without the spark plug boot and see if it will work for you. Sometimes the plug boot will conduct the ignition spark away from the plug to ground.