Your small craft will provide you with years of enjoyment. However, you need to make sure that it has enough power for your use.

Unfortunately, there’s no such thing as a boat motor size chart. Resultantly, you’ll have to figure out how to calculate the right sized motor for your boat. Fortunately, you’ve found this article.

Read on to learn how much horsepower per pound your boat really needs.


Onward to the Sea

There’s nothing like setting out for a day of fishing or jet skiing. For many, however, boating is a way to find peace and tranquility away from the responsibilities of daily life.

This kind of boating doesn’t require a lot of speed. Therefore, it doesn’t require a high-powered motor. However, small boats have weight and need sufficient thrust to navigate waves.

Luckily for you, it’s easier than you may think to choose the right motor size. However, you must put some thought into the matter because there’s no specific motor size for each craft.


What Is an Outboard Motor?

An outboard motor mounts on the boat transom. The transom is the flat square section at the rear of a boat.

During operation, you’ll submerge the gear case and propeller. When you’re not using your boat, you can tilt the outboard motor out of the water.

Tilting the propeller out of the water will prevent unnecessary corrosion and marine growth. Resultantly, outboard motors are ideal for either freshwater or saltwater environments.

Years ago, manufacturers made outboard motors solely with two-stroke engines. Now, manufacturers build environmentally-friendly engines that produce fewer emissions.

Today, outboard motors must meet strict Environmental Protection Agency (EPA) standards. Resultantly, modern, environmentally-friendly engines include direct fuel injection (DFI) two- and four-stroke models.

Also, contemporary outboard motors are more fuel-efficient. The engines run quietly and smoothly and produce little to no smoke compared to outboard motors from a decade and a half ago.


Choosing the Right Sized Outboard Motor

When choosing an outboard motor, you must make sure that it has enough horsepower for your vessel and your intended use. Lack of horsepower is a top reason that a boater quickly grows unhappy with their boat.

In part, you must match your horsepower needs to your anticipated boating activities. Instead, many people decide on horsepower by figuring out how fast their boat will go with the engine. However, horsepower is about more than speed.

An outboard motor may feel right when you test it at the dealership with 10 gallons of fuel. However, if you don’t choose an outboard engine with enough horsepower, the motor may perform dismally with a maximum passenger and cargo load.

Ideally, you should purchase an outboard motor with the maximum horsepower that’s acceptable for your boat. If you choose an outboard motor with too much horsepower, it will use too much fuel.

If you choose an outboard motor with too little horsepower, it will also use too much fuel. You may think that small outboard motors burn less fuel. However, a small outboard motor must work harder and therefore burns more gas.


How to Figure out the Needed Horsepower per Pound for Your Boat

The easiest way to start figuring out how much horsepower you need is by checking out the boat’s capacity plate or owner’s manual. If you don’t have access to these items, you can figure it out.

To do this, you must consider the horsepower-to-weight ratio of your boat. You can express the horsepower-to-weight rate in horsepower per pound.

Imagine that your boat weighs 6,000 pounds and has a 400 HP engine. In that case, 6,000 pounds divided by 400 HP would result in 15 pounds per horsepower.

You can also figure it out another way. For example, 400 HP divided by 6,000 pounds equals .06 horsepower per pound. By either metric, the smaller the number, the faster your boat will travel.

You must remember this ratio when you’ve decided on the necessary horsepower and you’re trying to match an outboard motor for your boat. Also, you must remember that carrying extra weight on your boat will consume some of the outboard motor’s horsepower.

You must also consider fuel efficiency. Ideally, your engine should run between 3,000 and 3,500 RPM.

If you choose a diesel engine, a quarter open throttle should produce the optimal speed. If you run a low horsepower engine at full throttle, it would use more gas than running a high horsepower engine with less throttle.


Play It Safe: Don’t Overload Your Boat

Horsepower aside, one of the most critical things you must consider when choosing an outboard motor is the maximum capacity. You should never overload your boat. Staying under the weight is more than safe; it’s the law.

Your boat’s capacity plate will tell you essential information such as the maximum number of adults, the maximum load, and the maximum engine size and horsepower that you can legally carry.

If your boat doesn’t have a capacity plate, there’s a formula you can use to figure it out. The formula is:

(vessel length) feet x (vessel width) feet ÷ 15 = (Number of people)

This formula only applies to outboard motors. You must never exceed this number when using one.

You Can Learn Something New Everyday

Now that you’ve done away with that pesky boat to motor size chart idea. You’ve figured out how to calculate horsepower per pound and you can start your hunt for a new outboard motor. Congratulations!

If you want to become an expert captain, you must commit to ongoing learning. Bookmark the FindBoatsForSale.com blog and visit often. In time, you’ll learn how to become a nautical expert. Have a question? Contact us here.