I was mowing with my push mower (brigs and Stratton) and suddenly it blew out a large amount of white smoke and stuttered to a stop. Later that day I tried starting it again and it almost started up but it sputtered and filled the area with a plume of white smoke. Now (a year later) I decided to attempt to get it running again. I am not sure about taking out the spark plug because I think it may need a torc wrench or something. I did however check to see if it would still spark one of my spare plugs which it does. The fuel in it is still the same so I may try draining it and re-filling it. It smells like gas. I have heard of water and oil being probable causes, could this be true. I know that it has mistakenly been filled with the mix of oil/fuel from my chainsaw's can. I drained it, but could there still be oil in it or something. Can I pull my spark-plug out with a mere crescent wrench and replace it?