I bought this new a few years ago m changed oil and filter when it was called for, this year the mower started to act funny, back fire when i released the kil switch, today there was no oil in the carnk case, it was on the floor, cleaned it up and filled the crankcase started it, ran a little rough not bad but still, started to smoke light blue/white color out of the muffler area, stopped the mower light blue smoke from the same area and the fly wheel, tore it apart didn't see where oil was from, put it back together, filled the to the mark, and let it sit, saw oil dripping from the air filter, is this thing toast?? or should i just run it until winter and get a new mower for next year? thanks.