What would cause my engine to lock up? Engine lock-up may be caused by a variety of reasons (such as low oil level, improper oil type, insufficient maintenance, etc.). To best determine the cause of failure, please consult a Briggs & Stratton Authorized Dealer for an engine inspection. NOTE: Please read and abide by any applicable Safety Information (PDF) before performing any engine work. This information is not meant to take the place of work performed by a Briggs & Stratton Authorized Dealer.