ALUM PROPELLER VOLVO PENTA STERNDRIVE MOTOR BOAT PROP

To some, choosing the right boat propeller can seem like a job for a marine service center. Anything that has to do with the backend of the boat can be a scary thing. Despite popular belief, choosing the correct propeller for a particular boat and motor is actually a fairly simple thing to do, once you understand what a propeller really is.

First think of propeller as a gear, whether it be on a car or even a bicycle. The lower the gear, faster hole shot, more power, but revolutions are much faster so at a point you can only turn that gear so fast until you over rev the engine (or you legs). Now think of your car stuck in only 5th or 6th gear, very slow out of the hole, little torque, but eventually it will catch up with itself so you can cruise to a good speed.

The same basic concept applies to propellers, except with a prop you are committed to only one gear". So what to do now? Find the prop size that will give the best overall performance. Sound difficult? It's really not.

Your engine has a recommended wide open throttle rpm range. Let take an example of an18' boat with a 125 hp engine with a rpm range of 4500-5500. In most cases you purchase a boat with some sort of propeller on it. Let's say this motor has a 21 pitch prop on it and at wide open throttle under a normal boat load, the engine turns 4900 rpms. Well it's in the range so it's the correct prop, right? Well yes and no. For the health and longevity of the engine it's okay, but for overall performance, you want to run a propeller near the top of the range. Well how do you change the size to get that?

Remember this rule of thumb: For every 2" of propeller pitch, rpm's will change approximately 400 rpm's. As you drop in pitch, rpm's increase, and as you go up in pitch, rpm's decrease. So if we want to raise our rpm's we should choose a lower pitch prop. Following the rule, going down to a 19 pitch should raise our rpm's to about 5300. That would help the hole shot and also gain us some more speed.

As you follow the rule of thumb, remember that sometimes rules are meant to be broken. This is not an iron clad rule, sometimes varying 2" of pitch will only change rpm's by 200. Switching prop brands or manufacturer, it can sometimes throw off the rule too.

At this point the most important thing to understand is that less pitch means more rpm's, more pitch means less rpms. For your boat to perform at its peak, you need to run at the upper end of your engine's recommended rpm range. That's it. Once you're there and still want more speed, handling, lift, etc, that's when choosing the right propeller brand comes into play.

Here's a simple adjustment you can make to improvement performance under varying boatloads: If you normally run with one other person on board, use that boatload as your measurement when determining your wide open throttle rpm's. But if you sometimes load the boat with 2-5 more people or try pulling a water skier or tube, get another prop 2" of pitch lower than your normal prop. It will compensate for added weight and drag and make a huge improvement on performance in these circumstances. But remember to keep an eye on you rpm's when running a lower pitch for these circumstances.

Most props have the size marked somewhere on the prop, either on the barrel, on the blades, or in the front or back of the propeller. Use that pitch that you're currently running as your starting point. If it's already running correctly then that pitch is your pitch.

This Prop Will Work on The Following Motors:

These are the available prop sizes you can choose from this listing:

This is what Turning Point has to say about their Hustler Series:

Turning Point's Hustler? High Performance Series aluminum propellers now feature the newly designed MasterGuard? Hub System. Created specifically to give boats a higher top-end speed, better handling, a faster hole shot and more efficiency, Hustler propellers maximize overall performance. The aluminum propellers incorporate the same high performance designs found in stainless steel props to give boaters a less expensive way to gain stainless steel?like performance.

The High Performance Series is designed for all engines ranging from 40 hp to 300 hp with 4-1/4" to 4-3/4" gearcases. The interchangeable hub allows boaters to save money on future prop purchases, since spare or different pitched propellers don't require another hub purchase.

Turning Point recommends that every boat have a spare propeller onboard to insure a day on the water isn't ruined by a broken prop or to allow for adjustments in different situations. Using a prop 2" in pitch less makes a big difference when more people are onboard or the boat is being used for watersports. The smaller pitch helps offset the added weight and drag on the motor and increases performance under these circumstances.

This map shows the approximate ground transit times for the continental US: