Choosing the correct outboard boat prop

Thursday, September 14, 2017

Once you have our outboard motor for your boat it is important that you choose the right outboard propeller as well. The propeller should be suitable for your type of boating, different props are available for shallow draft boating, for water skiing, trolling and for other types of boating. You also need to make certain that the prop will allow the engine to reach the manufacturers recommended RPM's when at full throttle or you risk damaging your propeller and engine. Choosing the right boat propellers is critical for the performance of your boat and for your boating enjoyment.

Boat propellers are often described by their diameter and pitch. The larger your engine in horsepower, the larger diameter prop you will generally want. The pitch describes how far the propeller advances with each revolution. A lower pitch gives better pulling power, however if you use a propeller with a pitch that is too low you won't be using all the power of your engine. A higher pitch allows the boat to go faster, but this is only true if you have enough horsepower to keep the RPM's at the optimum range. A pitch that is too large makes the propeller heavy and it demands more power than the engine can provide.

Boat Propeller Selection Guide

After determining the proper diameter and pitch you need to consider how many blades to have on your prop. Outboard propellers typically come with either 3 or 4 blades. Unless you are running a high horsepower motor or using the boat for bass fishing you will most likely want to choose a 3 blade propeller. 4 blade propellers are designed more for high speed usage with less steering torque and vibration at high speeds. Water skiers can also benefit from using a 4 blade propeller.

The next thing to consider is the construction material of the propeller. Outboard propellers can be made from aluminum, stainless steel, or composites. Aluminum is the most common choice for manufacturers factory equipment. They are inexpensive and easy to repair and they work well in a wide range of applications. Stainless steel propellers are more expensive, but they are also more durable and less likely to suffer damage. Composite propellers are often preferred for their durability and performance coupled with a low price.

Your main goal when choosing a propeller is to ensure that it allows the engine to perform optimally with a wide open throttle. Boat dealers can provide you with formulas to determine the proper pitch, diameter and number of blades based on your engines power or horsepower. The manufacturer may also be able to provide you with recommendations for good outboard propellers for your engine.

Deep Blue Yacht Supply has boating experts standing by to ensure you select the proper inboard or outboard boat propeller.