Maintaining Your Prop
Here are some tips for helping prolong the life of your prop, maintaning peak performance, preventing damage to other parts of your motor and saving some money on future repairs.
DO NOT use files or grinders on your prop to remove minor nicks or bends. This tends to cause the blades to become thin and may prevent us from being able to repair the prop. Also, by removing unequal amounts of material from each blade, you may be creating a different cause of vibration.
If your prop, skeg, or anti-cavitation plates become damaged, please DO NOT use JB Weld or similar materials to attempt your own fix. This makes it more difficult and more time consuming for us to be able to fix it, making it more expensive for you. Before we can fix whatever is broken, we have to remove all of the non-metal material before we can weld on it. If we are unable to fix something that has broken on your boat and know of no other way to fix it, we may recommend using those materials, but that's ONLY if there is no other reasonable option that we are aware of. We recommend asking for more opinions and options from other professionals to find the best ways to fix something.
Regularly check your skeg, gearcase, and underside of boat for nicks, bends, and any other damage (this includes loose rivets on aluminum boats). Damage in front of and in line with your prop can cause cavitation burns in your prop. The damage causes small bubbles to form and when those small bubbles pop on the prop, they actually burn through the paint and eventually the metal. This creates a weak point in the blade. The next time you hit something with your prop, instead of causing minor damage, you may lose the entire blade. Not all cavitation burns can be fixed as the ones above were. If you find damage, ask about getting it repaired to prevent any further damage to your prop.
Always check your cotter pin or tab washer before every trip on the water. Any tabs that are broken or wore out or if part of the cotter pin is missing, can cause the washer/pin to fail. Failure to these parts of your attaching hardware will cause the prop nut to loosen when in reverse. Eventually, and usually quickly, the nut and prop will come off while in reverse. Replace the washer/pin when worn or starting to break. Also, keep a record of what size/style prop you are running incase your prop is lost to the bottom of the lake/river.
If you run your boat on rivers or lakes within a river system, regularly check the diameter of your prop. River water contains a large amount of sediment in the water. That sediment, when your prop is spinning at several thousand rpms, acts just like a grinder or sander. Over time, repeated river running wears down the diameter, blade thickness, and cupping of the prop. Running a stainless steel propeller DOES NOT prevent this from happening. The picture above is of a high performance Yamaha stainless steel propeller that was run on the Wisconsin River and Lake Wisconsin (among many other bodies of water) almost every weekend all spring, summer, and into the fall for 3-4 years. It was missing almost an inch of diameter (3/8 inch or more from each blade) on top of most of it's cupping and the blades were thinning out. This customer's prop was almost worn to the point that we wouldn't be able to fix it. Having regular maintenance done annually (depending on how heavily you use your boat) can extend the life of your prop. Waiting until the prop barely pushes the boat any longer will guarantee you purchasing a new prop instead of being able to get it fixed. Allowing the prop to continually wear down without maintenance will increase your rpms and reduce your hole shot and top speed also.
Always carry a spare propeller. Carrying a spare propeller is no different then carrying a spare tire for your vehicle. If your prop is damaged while boating, especially while on vacation and out of town, it may very well end your boating for the day/weekend/vacation if you do not own and carry a spare. Finding a prop to purchase can be difficult, if not impossible, at times in some areas (especially in remote areas such as Canada). If you are able to find somewhere that does sell them, they may charge much higher rates since you have no other options available, they may not carry aftermarket brands that are cheaper, or they may not have the right pitch/prop available.
At least once a year or every time you change your prop, you should check behind your thrust washer for fishing line. As fishing line builds up behind the thrust washer, it can slide down into the seal housing for the prop shaft seal and cause damage. Damage to the prop shaft seal will allow water to enter the gearcase. Whether or not you fish does not make a difference. Fisherman that lose lures or whose line breaks off or loose line that falls into the water can get caught within your prop system. We find more fishing line behind the thrust washers on pleasure boaters then we do on fishing boats usually. EVERYONE should check for fishing line!