Propeller Repair and Alteration It is very important to have your propeller repaired if there is damage to it. Usually if the edges are missing pieces, curled edges or even slight damage your prop could be out of track. Causing vibration, cavitation or can even damage your lower unit if ran to long. Rake, pitch and sweep of all blades must be tru to each other. As an example: imagine your car with one flat tire. Your performance & gas consumption go out the door. Not to mention it will cause damage.