My Prop Looks OK, so It’s Fine… Right?
Published: Wednesday, September 30, 2020
By: Professionals of Henry H. Smith Co
Nothing has a greater impact on our boat’s performance than the engine’s connection to the water—our propellers. If we see nicks, dents, and deformation, the need for repair is obvious, but what about a propeller that looks okay? Are imperfections always visible?
As we prepare to tuck our boats away for winter, questions about our propeller’s condition typically cross our minds. Questions like:
- Was my propeller damaged this season?
- Am I getting the best performance possible?
- Was the propeller the cause of that noise or vibration?
- Should I have my propeller inspected?
These are all good questions. Let’s consider them one at a time.
First, propeller damage is not always easy to see. Over the course of a season, wear and tear take its toll on the propellers. Blades can be out of place and only measurement with the right equipment will confirm if they are not. Blade pitch is the most common measurement but rake and blade spacing can also be an issue that proper measurements can confirm. It is good to have a propeller professional check out your propeller every year or two to make sure all is within specifications.
Winter is a great time to review performance characteristics and make changes to ensure we are getting the most from our propellers. The key to making these changes is having adequate data to support the decision making process. Keeping records of boat performance relative to RPM will provide the necessary information to ensure the WOT (Wide Open Throttle) target can be achieved, but not over-shot. Dialing-in the WOT target is key to balanced, all-round, optimized performance and efficiency.
Noise and vibration are very closely linked and indicative of other issues with your boat. However, these issues are not always generated by your propeller. Noise, in simple terms, is a vibration at a frequency that you can hear and a boat can be a great ‘speaker’ for vibration coming from many places in the drive system. Ensuring your propeller is not the source by having the balance checked and reviewed for other signs of trouble (like cavitation) can help to resolve vibration issues.
Professional propeller inspection is the common thread here and will certainly help in answering all of your questions. A propeller professional will be pleased to evaluate your propeller and discuss any concerns. Even if the prop is not the source of the problem, it would be good to eliminate it from the list. Plus, the fall/winter off-season is a great opportunity to take the time to be certain.
About the Author
Founded in Detroit by Henry H. and William H. Smith, the company continues to employ 3rd and 4th generation members of the family, carrying on a legacy established in 1900 - to be your Marine Drive Specialists.
tags: Propellers, Service & Repair
