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Buying Guide

If you're new to boats, it's important you understand what you're doing before you buy a motor.  Owning a boat and a motor require basic skills for safe operation for both you and your passengers.  If you're willing to learn, being able to safely boat can open up an entirely new world to you for exploring waterways, fishing, and seeing things most others never will.  I strongly recommend reading and understanding the following information if you've never owned a motor or boat before.  There are some people who frankly, don't belong in boats or anywhere near motors, just like some people shouldn't ride a motorcycle, or snowmobile, or skydive.  Sailers don't necessarily know anything about motor operation.  Boating isn't like hopping in your car and turning the key, there is more to it than that.  There are plenty of bad operators who drive a car for years, even after passing driver's education and getting their state license!

When you leave shore in a vessel, you're for the most part on your own.  And if you are using a motor 25hp or below (for most states), you don't even need a boater's license!  So please make sure you are ready to commit to learning how to use a boat, and more importantly, how to operate an outboard motor safely.  It's that much more important to make sure you know what you're doing ahead of time.  I highly recommend taking a safe boaters course available through your local state licensing agency (most states require this for motors above 25hp anyway, even though it is rarely enforced).  I also recommend purchasing a membership to SeaTow (basically the AAA of the waterways) if you plan on going out on larger water bodies.  Towing costs are obscene, to say the least, if you ever get stranded, run out of gas, etc.

New Buyer's Quiz

Can you answer these questions?  If not, then you need to learn more about boats and outboards before becoming an operator.  Answers at the bottom of the page.

1.  In a 2-stroke motor, you should use clean gas to run it.

a.  True
b.  False

2.  The Starboard side of a boat is the equivalent of the ___________  side.

a.  Right
b.  Left
c.  front
d.  rear

3.  When shifting, you should move the shift lever ___________

a.  slowly, to prevent undue gear wear
b.  quickly, to prevent undue gear wear

4.  A motor choke does what?

a.  richens air input, leans out fuel input
b.  reduces air input, leans out fuel input
c.  richens air input, richens fuel input
d.  reduces air input, richens air fuel mixture

5.  When transporting an outboard off your boat, you should lie it down

a.  on the tiller side
b.  on the shifter side
c.  on the control panel side
d.  on the back/prop side

Know The Basic Aspects of A Motor

Just like your car or truck, you need to be familiar with the basic parts of an outboard motor before you buy it.  Understanding the different parts is akin to knowing the basic parts of your automobile for common conversations with other boaters.  If someone talked to you about your car hood, and you didn't know what the was, that might cause issues if you needed to check your car battery.  The same can be said for outboards; you should know what to look at if asked questions about your motor.

motor parts

What Size Motor Should I Buy?

capacity stickerCheck your coast guard rating plate to see the maximum horsepower (HP) your vessel can handle.  It is calculated by length, beam, and other factors.  If you overpower your vessel with a motor larger than what it's rated for, you assume exta risk and liability if you crash, if the boat flips, if it folds up like an accordian.  Don't try to turn a small boat into a jetski.  Go buy a jetski if you want more speed than what your boat is rated for.

For smaller vessels (typical aluminum boats, and smaller fiberglass/day cruisers), this rating plate will be on or near the transom.  For larger boats it will be near the engine compartment or at the helm.  If your boat doesn't have a coastguard plate anymore or is an older vessel, look up information on the boat utilizing the internet and do your homework.  If you have an obscure vessel or don't know what the model or make is, look for boats of similiar shape and size.  Underestimate your vessel rating to be safe, avoid overestimating.  You can always ask a local boat distributor for their opinion too.  Generally speaking aluminum boats are rated for lower HP ratings than fiberglass boats.

shaft length
Motor Shaft Length

This is another very common question. You need the right length motor otherwise your boat won't work properly and you can easily damage your motor or have safety issues while underway.  First, measure the height of your transom (the rear of the boat).  Measure from the top of the transom to the center bottom of the boat.  Using that number, you can figure out what you need for a motor length as follows:

~15" - short shaft
~20" - long shaft
~25" - extra long shaft

Note that if you already own a motor but don't know it's length, you measure from the bottom of the transom bracket (the part that hangs on the boat) to the ventilation plate (the flat plate directly above the prop).  This length is going to be close to the numbers above, give or take an inch or two.

You can use a longshaft motor on a shortshaft transom by installing a jack plate or mini-jacker on your transom to raise the motor height between 3-6 inches (based on vessels configuration).

Propeller Selection

Having the right size propeller makes a big difference in vessel performance and motor maintenence.  There are two main factors; diameter and pitch.  When you see a propeller described, you will see something such as 10 x 12.  This means 10" diameter, 12" pitch.  Pitch is referring to how much distance is covered during 1 revolution/turn of the propeller.  So in this case, 1 turn would equal 12" of vessel displacement.

Picking a propeller is based most importantly on top RPMs your motor turns under a typical load and calm waters/wind conditions.  Every motor has a normal RPM range.  Generally that will fall between 4000-6000RPM, based on the motor size.  The key factor here is knowing what RPM your motor is turning at wide open throttle (WOT, or max throttle).  You need a tachometer to do this.  The motor should be tested on your boat. 

Damaging a motor from turning too high of a RPM is generally not an issue as most motors after 1983 have RPM limiters built into their ignition systems to prevent over-reving. 

However, if you are turning too low RPM, you will have the motor 'lugging,' and that is very bad as well (overheat, burn out the internals).  Either scenario should be avoided.

If your RPMs are too low, generally each pitch DOWN you go, you gain 200-300RPM.

If your RPMs are too high, generally each pitch UP you go, you lose 200-300RPM.

A bigger pitch doesn't necessarily translate to more speed.  If you have high RPM, then yes, you should gain a few MPHs by going up in pitch since your motor can handle a bigger prop.  However, turning to0 low an RPM and using a lower pitch prop can actually help you gain speed.

I can evalaute your motor with a tachometer if desired, too.

Click on the image below to download an in-depth explanation on propellers and how to select the right one for your motor.


What Year Motor Should I Buy?

The year of the motor isn't as important as the condition.  Outboard motors are not the same as cars or trucks.  Automobiles are generally used everyday; outboard motors are used, in many instances, for 10-20 hours annually.   Most motors are tested during their design stages to withstand up to 1,000 hours of continuous running at wide open throttle (as fast as possible, high RPM, high stress). 

The condition of the powerhead and gearcase are most important; the other systems (cooling, fuel, ignition) are all perishable and will need to be serviced and renewed at regular intervals as part of the normal maintenence schedule.

Unlike the majority of used motor sellers, engines sold by Riverside Outboards LLC have already had all the necessary servicework performed, and the powerhead and gearcase are thoroughly evaluated to be functioning properly. 

In most cases the price to buy a reconditioned motor from Riverside Outboards is less than motors sold by 'flippers' who haven't even serviced the engine at all!  Don't worry as much about the year, pay attention to the condition!

Quiz Answers:  B, A, B, D, D.  These are very basic questions, if you have any incorrect, please read the education section and the operator's manuals I include for free on this website!
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