I went out to start my Sears Craftsman Hydrostatic lawn tractor and it would turn over and over but would not continually fire enough to start. I took the air filter apart and cleaned everything, replaced and the tractor started right up. I cut grass for about and hour, then turned off to put things back in yard. I got back on and it did the same thing, turns over and over and over and will fire once in awhile but not enough to start. It is full of gas, the blade is disengaged and the deck is up as should be when starting. My husband is out of town and now its sitting down by the lake. Help!? Please :)

Hi,
Bad spark plug.
Peace,
Clarke