I just bought a new mower with a Briggs&Stratton engine. The engine has NO OIL DRAIN PROVISION!
Honest, there is no drain plug. The manual suggests using the oil fill port to drain the oil. This means either removing all fuel, and turning the engine on it's side or purchasing a pump that may or may not remove all the oil from the crank case.
Say "Good-By" Briggs&Stratton.
Next mower will have another brand of engine. Any manufacturer who would decontent (that's what it is called.) to the point the owner is inconvenienced just isn't my kind of company.
Review about: Briggs And Stratton Engine.