Skimming across the surface of a placid bay, the boat company rep explains the advantages of his product. He mentions that with this particular craft a change in the prop can improve performance.
Just how does the pitch of a prop or the content material affect the performance of a boat? If a prop specialist knows the desired performance the boat, he will tune the prop to get the highest level of performance out of the craft.
In choosing a prop for a boat, manufacturers will recommend a range of rpm. The prop will govern that range. The prop specialist tries to set up a boat at the top end of the recommended range. Every one degree of pitch is worth 250 rpms.
Usually when you drop down in pitch, a little bit of speed is lost. However, the hole-shot will be a lot better. It seems that is the concern of most anglers. Some people really want that top end speed. If one is in shallow water, the hole-shot is what will get you out. If you sit there and plow in the water, you will be hitting everything underneath the surface. That includes rocks, stumps etc. A good hole-shot will get you out.
The diameter of the prop is another consideration. Every 1/4 inch of diameter is worth 150 rpms. If you have a boat motor, that is a little high on rpms and you want a quick fix, just shave the prop down 1/4 inch. That will bring the rpms back up.
The surface area of a prop is critical and different on pontoon boats. A bass boat style prop does not have much blade surface. The more blade surface you can turn the more rpms. Pontoon boats need a motor that will push it not lift it like a bass boat. They need more blade surface and a lower rake. The rake is what creates lift on your boat. There is a steep rake angle for bass boats because you want to lift the bass boat out of the water. A low rake angle of five to a 0-degree rake is for pontoon boats requiring push not lift. Owners of pontoon boats want to take all their motor horsepower and put it toward pushing. Pontoon props will have a low rake and a lot of blade surface.
When buying a boat, manufacturers install the prop that will be of benefit to the customer for any area of boating he seeks. Then it is up to the customer to determine what more he wants from his boat. When the customer talks to the salesperson, it is up to him to explain what use he plans for the boat and where he will use it. Usually, the dealer will have a good idea from other customers as to what prop to install.
The customer who is bass fishing in the shallow waters is bound to hit something eventually. Just a nick in a prop blade you will lose about 3 mph. Just a nick that you can feel with your finger will cause it to cavatate. The cavitation is bubbling. When the blade slices through the water, it needs a nice clean slice. If you get the nicks on there the slicing is creating those bubbles your performance suffers. It is grabbing in spongy water. It is not going to have that true bite needed for performance.
A prop with a nice clean edge on it will always have a clean bite. That is where you get your performance. It does not have to be a sharp edge just a clean one.
Prop shops receive them bent, gouged or even with a tear in the blades. Once welded they usually will run better than right out of the factory. That is because every blade is true to each other. Factory-produced blades are not always exactly alike and true. Manufacturers recommend the tuning of props.
Tuning is taking every blade and making them the same. In the pitch, one-degree difference is 150 rpms. Props can be two to three degrees off from each other. If each blade is exactly true, it makes props run more effectively.
If a person is serious about his boat performance, the first thing to do when he gets delivery of the boat is to take the prop off and get it tuned. There are people who spend thousands on their motor to beef it up when all they really have to do is focus on the prop.
In general, props are usually repairable. They can have extensive damage. As long as it is still attached, the blade is repairable.
When it comes to maintenance, keep the blades edges clean by using a file on them. For the traveling angler the file keeps those nicks off. Nicks kill performance. As long as the nicks are small, a file used on them will not affect the balance significantly.
Balance is critical for high performance. There can be a little bit of a vibration. Unfortunately, extreme vibration will ruin a prop. It is better to install a new prop.
DON GASAWAY'S BLOG 