The best propeller pitch for pontoon boat provides the best performance.
Too little pitch and the propeller spins wastefully on an over-revving engine. Too much pitch; on the other hand, slows down the propeller as the engine labors too much.
You can play around with propellers on a trial and error basis, trying to find one that will match your pontoon boat’s hull shape, weight, and engine output.
But here is the thing, trial and error is time-consuming and can be costly unless you find a dealer who can allow you to test out his or her props one by one.
So! How can you determine the most ideal propeller pitch for your pontoon boat? Let’s find out!
- 1 What is a Propeller Pitch?
- 2 What Considerations Do You Need to Make?
- 3 The Best Prop Pitches You Can Consider for Your Pontoon Boat Are:
- 4 Which is Better for Your Pontoon Boat – Three or Four-Blade
- 5 Our Prop Recommendations for Pontoon Boats
- 6 Final Thoughts
What is a Propeller Pitch?
A prop pitch refers to the angle of the blades. For example; if you think of a screw moving through a piece of wood.
A pitch; therefore, is the amount of distance that a propeller would travel in one revolution if it was moving through a solid medium.
So, a nineteen pitch prop would move nineteen inches while a fifteen pitch prop would move fifteen inches.
The higher pitch of the propeller, the faster your pontoon boat is going to sail.
But what is most important is that you find the correct and exact pitch that will be perfect for your boat.
What Considerations Do You Need to Make?
There are a few important things you need to take into consideration when looking for the most ideal pitch for your pontoon boat. These include:
- High Vs Low Prop Pitch
- The Holeshot
- The weight of your boat
- Prop Slip
- Existing prop
The two most important sizes that define a prop are diameter and pitch. The diameter refers to the distance in inches across the circle made by the blade tips as the prop rotates.
Pitch as we have seen above is the distance in inches that the prop moves forward with each three hundred and sixty-degree revolutions, assuming that there is no slip.
Prop pitch can increase or decrease your pontoon boat’s performance, acceleration, top speed, and torque.
High Vs. Low Prop Pitch
When you have a propeller with a high pitch, you have reduced revolutions per minute and higher top-end speed.
With a low pitch prop, you get increase revolutions per minute and improved holeshots.
High pitch props have no problem hitting top-end speeds. But the bad news is that high pitch props tend to accelerate poorly when under load.
A heavier pontoon boat; therefore, would require a flatter pitch prop for decent sailing power.
What is a holeshot?
Some props are engineered for speed, while others for power, still others for the fast hole shot.
A holeshot refers to the ability to get your pontoon boat up on a plane.
Props; nowadays, are a compromise. An attempt to blend several features to achieve a specific goal.
A typical holeshot prop gives up some speed at the top end in return for getting on a plane in just a few feet instead of a longer distance.
For pontoon boat captains, the challenge is to find a propeller that gets the boat on a plane within an acceptable amount of time while still providing a good sailing speed and giving up as little on the top end as possible.
Things that affect the holeshot are hull shape, the type of engine, and the type of propeller.
If you have a cathedral shaped hole with a prop with multiple blades (more than three) you are likely to get up on to the plane and have a quicker holeshot than a watercraft with a deep free hole and three blades.
This is a measure of how efficiently your pontoon boat is going through the water. If the prop doesn’t slip at all as it cuts through the water, then each rev propels the boat forward.
For example, a fifteen-inch prop propels the boat fifteen inches in one revolution.
Due to prop slip; however, your pontoon boat tends to go slower than the theoretical speed. This is normally about ten to twenty percent slower at top speed for faster vessels.
The diameter of a propeller is the distance across a circle swept by the tips of the blades. It generally correlates the size of a boat and the engine.
The diameter increases as you go down in pitch and decreases as you go up in pitch. The choice of prop diameter depends on your vessel and engine type.
So, small diameter props are linked to low weight vessels. Those with low engine mounting height or if you are looking at high-performance vessels.
If you have an incorrect diameter that is too small, you will find that you are underpowered with an increased rpm.
If the diameter is too big; however, you will find that you have increased resistance and decreased rpm.
Number of Blades
The number of blades you choose depends on whether you are sailing a recreational or high-performance pontoon boat.
The standard is three blades, which means you have a slightly higher top-end speed.
The boat; however, takes longer to plane and it is slightly cheaper compared to four or five-blade props.
Four and five-blade propellers tend to have a faster holeshot and superior holding in rough waters.
They are better at low-speed handling and they have a better performance in the mid-range rpm.
Weight to Horsepower Ratio
You have to make this consideration when calculating top speed.
The weight to horsepower ratio refers to the total weight to be propelled divided by engine horsepower.
The weight of an empty pontoon boat is in the manufacturer’s brochure or you can inquire from the dealer.
Add the weight of the engine, the number of people onboard, fishing and boating gear, and gas tank to the weight of the boat. If the total comes within one hundred pounds, that is close enough.
Let us say your pontoon boat weighs one thousand five hundred pounds and it normally carries four hundred and fifty pounds of load.
Dividing the one thousand nine hundred and fifty pounds total by the engine horsepower of fifty (for example) generates a weight to horsepower ratio of thirty-nine.
On a conventional planing hull, one horsepower should push thirty pounds at thirty miles per hour.
So, each difference of three pounds alters the speed two miles an hour. This means the greater the weight, the less the speed and vice versa.
Wide Open Throttle (WOT)
The simplest measure of speed performance is the wide-open throttle speed. The speed for displacement pontoon boats varies directly with power loading.
The speed is plotted as the speed in miles per hour divided by the square root of the waterline length of the vessel.
Engine Rev and Prop Pitch
The engine labors at low rpm and the boat struggle to overcome the hump. The prop bites off more than it can chew.
With reduced pitch, the prop would let the engine rev higher from the beginning.
The propeller thrust produced per rpm would be less, but the higher rpm would actually produce more thrust.
Fuel consumption may go up a bit because fuel is directly proportional to horsepower.
But the increase in acceleration would be worth it. The danger in reducing prop pitch is that without the load, the prop will let the engine over-rev at full throttle.
What is the Existing Boat Motor and Prop
Take your existing boat motor and propeller in the water and run a few tests.
Just to see where your current prop is operating from a wide-open throttle rpm standpoint.
To do that, we generally recommend topping off your pontoon boat with fuel. But keep it otherwise lightly loaded versus the typical outing in the water.
You should warm up your watercraft for around five minutes to get the engine at the right operating temperature.
When in the water with no other vessels nearby, give your boat full throttle. Then trim the engine up for speed.
Once you have maximized your speed, you have to record what your wide-open throttle would be.
The ideal WOT range is five thousand seven to five thousand eight hundred revolutions per minute.
What happens if you have done a test and your RPMs are running outside the recommended range for your boat.
This simply means you can handle a little bit more pitch on your prop. In such a situation, you probably have to add one to two inches of pitch.
Generally, for every inch of pitch, you are going to be dropping rpm by about one hundred and fifty to two hundred rpm.
Most propellers you will come across come in two-inch increments. So, by moving up in pitch, you may be dropping your engine in rpm as much as four hundred rpm.
If your pontoon boat; however, has too much prop on it; in that case, you would want to go down one inch or two inches of pitch. That is going to increase rpm by about one hundred and fifty to two hundred rpm.
The Best Prop Pitches You Can Consider for Your Pontoon Boat Are:
- 13.8-inch diameter by 10-inch pitch
- 13.8-inch diameter by 11-inch pitch
- 13.8-inch diameter by 13-inch pitch
Which is Better for Your Pontoon Boat – Three or Four-Blade
A larger percentage of boats out there use a three-blade prop. So, why would you want to go for a four-blade? The answer is simple.
A four-blade propeller has a superior surface area and bite. That will allow your pontoon boat to get up on plane and be able to keep the plane easier at a lesser rpm.
A three-blade prop has less surface area, less drag, and it will provide more top speed compared to a four-blade.
Why a four-blade is highly recommended for a pontoon boat. If you are out on the ocean or lake, the conditions are constantly changing and there is hardly ever a time where you can run flat out all the time.
The larger size of most pontoon boats will do well with a four-blade prop because when the waters get rough and you need a lot of control.
You will need more bite to be able to maintain the boat in the correct direction and to keep it in the ideal speed.
You would also want a four-blade if you will be carrying a heavier load on your pontoon boat, which includes boating or fishing gear and passengers.
Our Prop Recommendations for Pontoon Boats
Based on our findings, we recommend the following propellers:
Mercury Spitfire 4-Blade Pontoon Boat Prop
- Diameter: 13.8 inches
- Pitch: 11 inches
- Material: aluminum
- Rotation: right hand
The Spitfire is a four-blade aluminum prop that gives you high performance in an economical package.
It is all made possible by its revolutionary design. The 13.8-inch diameter is smaller. The prop can spin faster and give you that good acceleration and holeshot.
This model has a straight trailing edge and real aggressive cupping. That allows this prop to grab the water.
When making a fairly sharp turn, this prop will not blow out and it is going to keep holding the water. The 11-inch pitch is just perfect for most pontoon boats.
Quicksilver Nemesis 4-Blade Aluminum Prop
- Diameter: 13.8 inches
- Pitch: 13 inches
- Material: aluminum
- Rotation: right hand
The Nemesis four-blade aluminum prop will improve performance on twenty-five to two hundred horsepower outboards and stern drives. The small diameter and pitch provide superior acceleration.
The four-blade design delivers superior holding and handling in rough waters and tight turns.
The Nemesis is compatible with most manufacturer’s outboards and stern drives. It is one of the best options for pontoon boats.
Prop pitch is governed by your pontoon boat’s speed and shaft rpm.
Diameter; on the other hand, is determined by engine power and shaft rpm with adjustment made for the number of blades and design of the prop.
Overall, the best prop pitch must be that which will give your pontoon boat its anticipated speed plus an additional allowance for prop slip.