Selecting A Propeller
Our Goal at Gander Mountain is to make choosing
a prop as easy as possible. Feel free to browse the
information below to gain a better understanding of how
to select the right prop for your boat.
If you want to skip this information
and go on to our prop tool, click here.
If you already know the item number
for the prop you need, please enter the item number
into the search box at the top of the page.
Selecting the right propeller is an important factor in maximizing
your boat's performance. Determining the correct size and style of
prop will keep the engine operating within its recommended rpm range
and allow it to apply its maximum horsepower to the water.
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Michigan Match Aluminum |
Stiletto Stainless Steel |
Comprop Composite |
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Apollo 3-Blade Stainless Steel |
Solas Stainless Steel 3-Blade Propeller |
Solas Aluminum 3-Blade / 4-Blade |
Not All Props Are The Same!
Size — Props size is are described by referring to
diameter and pitch. Diameter is twice the distance from the center
of the hub to the tip of any blade. Generally smaller diameter
props correspond with smaller engines and boats, while larger diameter
props correspond with larger boats. Pitch is the forward movement
of a propeller through one complete revolution measured in inches.
Lowering prop pitch will increase acceleration and pulling power.
A higher pitch prop will make a boat go faster as long as the engine
has enough power to keep the rpms in the optimum range. If the
engine doesn't produce enough power to run a higher pitch prop
all performance suffers and engine damage can result. So - select
the prop size that lets your engine operate at WOT within its correct
rpm range.
Number of Blades —When the number of blades are changed,
diameter and pitch may require a minimal adjustment to keep the
RPMs in the proper range. For most purposes, 3 and 4-blade props
can be used interchangeably on outboards and sterndrives without
much of a change in performance
Material —We offer propellers made of composite, aluminum,
and stainless steel. Composite props offer good performance, are
durable, and inexpensive. They also offer some protection for your
lower unit during a prop strike. Aluminum props are the most common
and are suitable for the widest range of applications since there
are so many models and styles available. Stainless steel props
offer the highest performance and best durability.
| |
Weight |
Flex |
Repair |
Cost |
| Composite |
Least |
Little |
Not Possible |
Least |
| Aluminum |
Medium |
Little |
Easy |
Medium |
| Stainless Steel |
Greatest |
Least |
Difficult |
Greatest |
Cupped Propellers —Special curved
trailing edges enable the prop to maintain performance at higher
trim levels and in tight corners. Cupped props allow most boats
to achieve a higher top-end speed or at least the same speed
at a lower engine RPM. They also promote more efficient fuel
consumption.
Wide Open Throttle (WOT) rpm Range —When selecting
a prop, the goal is to choose one that allows the engine to reach
its optimal WOT. This is generally between 5000 and 5500 rpm
for outboards, 4400 to 4800 for sterndrives, depending on engine
type. This information is included in the owner's manual of a
new boat or engine.
Replacement Considerations
If your current prop's performance is acceptable (WOT
is within manufacturer's guidelines) -- Choose
a replacement prop that is very similar to the diameter and pitch
of your current prop. You might consider upgrading to a different
material such as stainless steel or trying a 4-blade prop instead
of a 3 blade.
If your current prop is unsatisfactory —What if your
engine operates at the wrong rpm at WOT? Pitch and rpm have an
inverse relationship. Increasing pitch reduces rpm and reducing
pitch increases rpm. A 1" change in pitch will usually result
in a 200 RPM change in engine speed. Therefore, if your engine
operates below the optimum proper rpm, you should consider a
propeller with less pitch. If your engine over-revs, consider
increasing the pitch.
Example: Your sterndrive tach limit (red line or rpm limit) is
4800. Your motor at WOT with full trim only turns 4300 rpm.
Buy a prop with 2 less pitch to bring it up within 100 rpm of
your tach limit. Your acceleration will improve and your top
end will stay the same or improve because your engine puts out
more power closer to its rev limit.
You might also consider changing the propeller size to affect a specific
performance attribute. A lower-pitch power prop makes it easier to
pop skiers out of the water. Tournament bass boats may need more
top end speed and should use a prop with a higher pitch. Houseboats
and cruisers care more about efficiency at displacement speeds, therefore
they require a lower pitch to achieve low-end power and the largest
diameter their lower unit can handle.
What's New With Propellers? Modular propellers are becoming
increasingly popular. In fact many engine manufacturers are now
selling modular props as original equipment. Our current offering
of modular props includes Michigan Wheel XHS Propellers in both
Vortex Aluminum and Apollo Stainless Steel.
How To Order A Modular Prop
When ordering a modular prop, you'll need to order both a hub kit and a prop
housing. First find your engine in the charts and order the hub kit that matches
your application. Then select a propeller housing from the corresponding series
that suits your boating style or is the closest replacement for your old prop.
Different props for different applications
If you regularly run your boat at different altitudes,
you know the importance of using props with a different
pitch to match your engine performance. Maybe you have
several different uses for your boat weekend cruising,
wakeboarding, fishing, etc. Having two props pitched
2" apart lets you optimize the power of your
engine. Modular props allow you to save money on that second propeller.
Be Prepared Always have an extra propeller on board with
tools to change your propeller. If you have a prop strike or spin out a
hub you will only be delayed a few minutes and not miss out on all the fun.
Let Gander Mountain Help
If you need help in selecting the correct propeller, try our
online prop selector guide or
call us at 1-888-542-6337, and one of our friendly technicians
will gladly assist you. When calling, please have the following
information available: engine year and horsepower, rpm range at
wide open throttle (WOT) with loaded boat, and any numbers stamped
in the hub of your current prop.
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