When should I replace a worn propeller?
We recommend replacing your prop if you have lost at least 1/4" of its original diameter. If your prop is worn by just 1/4" you have lost most of your cup, and thrust. This will lead to poor performance, and higher RPM's which put's more strain on your engine.
Propeller Removal:
Hex- Hex hub props were designed for easy removal. Most of the time they will simply slide off, but sometimes they require a few taps from a dead blow, or non marring hammer. A light application of anti-seize will prevent this in the future.
Threaded- Longtail- insert a strong screwdriver, or punch through the universal joint to keep the shaft from spinning. using a deadblow hammer, hit the end of the blade counter clockwise, gently at first. If it requires more force use a block of wood so you don't damage the prop. If it will not spin, you may need some heat from a torch. DO NOT overheat, or you will melt your seals. Try the hammer again. If it still will not budge, you may need to cut the hub in half with a grinder equipped with a cut off wheel. This is a delicate process. You do not want to cut into your shaft threads. Cut just deep enough that a solid whack with your hammer will break it into 2 pieces.
Propeller Balance:
If you start to feel excessive vibration in your tiller handle, your prop may be out of balance. This can be caused by dings, cracks, or even a bend that is not visible. Vibration will lead to serious issues like cracked mufflers, drive components, and even carburetor problems.
You can check for vibration by running your engine on the trailer at about 3000 rpms. Watch the skeg in front of the prop. if it is shaking or blurry looking, you have a problem. Remove the prop, and test it again. If the vibration stops, it's time to replace the prop.
Removing Chips:
If there are dings in your prop with any sort of jagged metal, you should clean them up with a file, or grinder for 2 reasons.
The jagged edges are extremely unsafe, and will slice open your leg, or your dog in a heartbeat.
These jagged edges also cause cavitation, and unbalance.
Only remove as much metal as necessary to get it back inside it's original footprint.
Shaft Lubrication:
Each time you remove your propeller it is a good idea to lubricate the threads, or hex with anti-seize. This will save you a big headache when it is time to remove it again.