24 hp briggs and Stratton commercial turf on this lawn mower. It has compression, air and gas, but it doesn't seem to matter if I pull off one sparkplug wire, if I pull the other one off instead it stalls. The funny thing is it doesn't even seem like it is missing! Any ideas?

I would start the engine and then test each spark plug wire for spark. You could slightly pull the wire from the plug, let it touch the plug and then start. Using pliers retract the wire slightly from the plug and see if there is spark. BTW have you removed both plugs too inspect?

I would start the engine and then test each spark plug wire for spark. You could slightly pull the wire from the plug, let it touch the plug and then start. Using pliers retract the wire slightly from the plug and see if there is spark. BTW have you removed both plugs too inspect?