Don't think being overfull is the problem. Been running and using it most every day since I changed oil 6 months ago. and have had no need to add. I was on the golf course when it started smoking. I may gotten at an angle while looking for balls out of bounds that may have caused some problem. I think I will change oil, and fill it a little shy of full. Have been using 10W40, believe I may go with a 30w, do a compression check and go from there. thanks all.........