Honda Lawn Mower Leaking Oil From Bottom . Joined oct 6, 2016 · 2 posts. Drain the engine oil and fuel from the engine. Had a 265 delivered Sunday. My Lawnmower Forum from www.mylawnmowerforum.com It started shortly after i bought the mower and keeps getting worse. Generate milky oil by mixing oil and coolant due to hidden leakage in the engine passageways. In addition, inspect the fuel shut off lines for cracks or tiny holes.