My lawn mower (Briggs and stratton 650 series/6.50) just bought 3 months ago won't start. Couple weeks ago I realized I put too much oil and it was smoking all over, reduced the oil and I was able to do my work. Today I tried over and over to start it and it will only kick and stop but the machine is not running. Any feedback will be highly appreciated.

Thank you
Smith

Um, the valves may be the problem, or a sheared flywheel key, or the cylinder is full of fluid.