Your boat propeller works by changing the engine's power into a thrusting that moves your boat forward. Knowing how to do basic propeller repair and maintenance tasks can go a long way in helping you take proper care of your boat without spending excessive repair technicians' costs.
Check the blades on your propeller for nicks or bent parts. These are all signs of propeller wear that typically signal time for a propeller replacement. Any problems with your propeller blades can hinder the job they do for you and can hurt the engine. If your propeller has worn blades, your engine can be damaged further by improper acceleration.
Mold any dings out of your propeller. If your prop is just a bit dinged up after a tough sail or impact with an underwater obstruction, it is possible to simply reshape it a bit. It is best to make a mold of the original prop in new condition where the blades are still at their original angle, and then use this mold as a guide when reshaping your prop after impact.
Make sure your hub is not slipping. If the propeller hub is the problem, your boat won't move at all even when you hit the gas. To fix this problem, remove the propeller, and mark the end of the propeller housing and the hub and keep the marks in line with one another. Install a new propeller to see if that fixes the problem. If the marks are out of line, your hub is slipping.
Balance your propeller. This can usually only be done by a certified technician, but making sure your propeller is properly balanced ensures that it runs free of any troublesome or even dangerous vibrations.
Test the bush and exhaust ring. If the propeller has a rubber bush, then this is ordinarily dry torque tested, and the exhaust ring should be inspected for any damage. Make a note as to whether either of these parts need replacing, and then take them into a good repair technician for replacement parts if necessary.