Shopping for the right boat propeller can turn into a technical nightmare. Fortunately, with the right guidance, it doesn’t have to be! We asked two experts, Eric Johnson from OJ Props and Jim Thelen from Acme Marine, for the scoop.
By Tina Santelli
What is the real purpose of a propeller?
Propellers are kind of like the shoes on your feet. If all you’ve ever worn is uncomfortable shoes, or the wrong size, you don’t know what you’re missing because you are unable to relate to the experience of extremely comfortable, properly fitting shoes. Likewise, the right propeller for your boat can increase fuel efficiency, reduce vibration, minimize speed fluctuations, maximize the life of the engine, increase acceleration and/or speed, enhance wake characteristics and improve the overall performance and handling of your boat.
What information do I need to know what prop is best for me?
The main use of the boat is very important in choosing the right propeller, as the needs of wakeboarders and three-event skiers are very different. For the wakeboard/wakesurf enthusiast, any information regarding the amount of ballast typically used will be helpful. For the three-eventer, the rpm at skiing speeds of the current setup is useful in determining the correct size. There really is not a one-size-fits-all propeller choice, as each boat is different and so are the needs of each application.
What kind of prop should I have as a three-event or recreational skier?
If you’re looking for faster top-end speeds for hard-core skiing, stick to the three-blade. But if you’re a recreational three-event skier who dabbles in wakeboarding and wakesurfing with a V-drive boat, a properly fit four-blade propeller with a lower pitch would be the most ideal option for you since it can allow your boat to be heavily ballasted without losing performance. If you don’t feel comfortable making the decision based on a recommendation, though, take advantage of trial programs offered by some prop companies that let you try different prop sizes and pitches to determine what best fits your needs.
How can changing my prop affect my driving and skiing?
Even the average boater and skier are astounded by the improvements a suitable propeller makes in the smoothness and performance of their boat. Most times, a new and ideal-fitting prop can make an old boat seem new again! Nevertheless, there are some very important things to be aware of when choosing an inboard propeller. As is the case with any propeller, it is absolutely essential to choose the correct size for your boat, engine and application. Also, be aware that even though the propeller can make a huge difference in boat performance, it is still only one determining factor. The engine, transmission and hull, etc., must also function properly in order to achieve optimum performance.
What can go wrong if I have the wrong prop on my boat?
The maximum rpms, or wide open throttle (WOT) rpms of an engine is an important benchmark, often used to determine the best-size propeller for a particular boat and application. By choosing a propeller with the correct combination of diameter, pitch and cup, etc., the WOT rpms should be in the proper range to provide optimum performance for the boat and engine at all levels of operation. But fitting your boat with the wrong size propeller can translate into a variety of concerns (i.e., poor hole shot, over- or under-revving, hitting the rev limiter, causing damage to the engine, etc.).