My Murray 14 hp Briggs Stratton started up fine after several months of sitting up. I ran it for about 30 minutes starting up and stopping frequently. The last time I tried to start it the engine would not fire up. The starter works fine, I drained the gas tank and put new fuel in, took the plug out and cleaned it. The plug was wet, but I think I am not getting spark. Could the magneto all of a sudden go bad? Or should I check something else?

More than likley a fuel delivery problem. Remove the air filter and put a little fresh fuel in the carb intake. Do not put it on choke and crank, if it starts and dies you need to check the fuel system further.

Allways put in a new plug, take the time to pull it just replace it.
Ignition failure is the least likley problem.
Don

Thanks for the suggestion. I put in a new plug, put gas in the carb and no go. I checked for spark by pulling the plug and cranking with the plug attached to the spark plug wire and no spark visually or by actually holding it in my hand. Any suggestions?

It sounds like a ignition problem, the safety switches shut down the ignition to kill the engine, it may be a bad seat switch or blade engage switch. I would locate the wire coming from the ignition coil (small black) comes out from under the fan shroud and goes to carburetor. Remove this wire from its terminal, there should be all the safety kill wires from the tractor there. By removing the ign wire you are eliminating the possibility of a bad switch.

Don

You hit it on the head! After removing the black wire from the magneto it fired right up. Many thanks!

That is just a SYMPTOM you need to find the cause. There is a bad switch somewhere.
Don

That worked for mine as well! Only the wire on mine was green. I think I'm just going to wire a toggle switch in line and turn the switches back on once I've started the mower. Seems easier and cheaper than replacing all of them to find the right one. Lazy man's way...

That worked for mine as well! Only the wire on mine was green. I think I'm just going to wire a toggle switch in line and turn the switches back on once I've started the mower. Seems easier and cheaper than replacing all of them to find the right one. Lazy man's way...

If you jump the safety switches one at a time until you find the right one,then you will only have to replace the bad one.
Safety First .
Luck