I have a one year old Troy-Bilt Pony with a 17.5 PowerBilt engine and I'm having issues getting it started. I could smell gas and pulled the plug and with the plug wire attached, I turned the key over and no spark. I replaced the plug and it started right away. The very next day same problem; no spark at the plug but when I stuck a screwdriver in the plug wire and turned the engine over, a spark was visible. I replaced the plug yet again and it cranked right up but very next day same problem again. What could possibly be causing my spark plugs to foul out so quickly.