How to Test a Boat Motor out Of Water

Last Updated on October 1, 2022

An essential aspect of your boat’s maintenance routing is testing the motor out of water. You can flush the motor and test its functionality to ensure that it is always in good working condition.

Testing a boat motor out of water

There are two methods for testing your boat motor out of water.

Method 1

This method involves a few steps:

Step 1

Locate the water intake in the motor and decipher if it features an attachment for connecting the hose. If it has an attachment, then you will connect the hose. Otherwise, you will need motor muffs.

Step 2

Connect the hose to one of the motor’s water intakes if it comes with one. If recommended by your manufacturer, you will seal the other intake with tape.

If your motor does not come with a hose attachment, connect the muffs to the motor. As you connect the muffs, ensure that they stay firm. To allow for a firmer hold, you can wet the inner part of the muffs before attaching them to the motor.

If the muffs are firm, it will prevent them from disconnecting from the motor when the engine is running. Attach the muffs strategically to position the connecting rod opposite the propeller.

Step 3

Connect the garden hose to the muff with a nozzle. Ensure to connect it firmly.

Step 4

Turn on the water supply. Consult your user manual to know what pressure the manufacturer specifies.

Step 5

Put the engine on neutral. Then, start the engine. Depending on your engine, you can turn it on with a key or by pulling the starter. Some engines come with push buttons you can push to start them.

Step 6

When you turn on the engine, check the machine’s upper part. If the water overflows, then the pump is working well. If there is no overflow, the pump may not be in good shape.

You will have to turn off the engine and check the tube for blockages. Most likely, debris and dirt hinder the flow. Check out the tube with a wire and feel for blockage. Take out every debris if there is any there.

After this cleaning and unclogging, there should be water flow through the tube. If nothing happens, the tube might be damaged and you need to replace it.

Step 7

If the water overflows, leave the engine to keep running for the number of minutes specified in your user manual. Otherwise, it is safe to let the engine run for 5 to 20 minutes. Within this time, you would have successfully flushed the engine, if that is your aim.

Step 8

Turn off the engine if you have tested it enough. Then, stop the water supply. It is recommended to turn off the engine before stopping the water flow. Running the engine without water is dangerous to the engine.

Step 9

Disconnect the hose from either the built-in attachment if your boat motor has it or the muffs if you used them. Remove the muffs from the motor and keep them.

By this stage, you have successfully tested your boat motor out of water. it is advisable to drain the water from the powerhead before keeping it.

Method 2

This method also involves a few steps:

Step 1

Put the boat motor on a stable suspended platform and submerge the propeller in the water. The platform you place the motor on should be high to let you conveniently put a bucket of water under it.

Step 2

Put oil and gas in the can. Before you put in new oil and gas, ensure that you pour out the old one because it might be contaminated. Put the quantity of oil and gas specified in the accompanying manual.

Step 3

If you have kept your motor for a while, you may need starting fluid. To apply the fluid, remove the rubber shield from the sparks plug so it gives you access to the air filter and cavity.

Step 4

Start the motor by pulling the cord. If it is difficult to start, use a 12V battery. You can jump the motor as you do a car.

Tips for testing a boat motor out of water

  • Ensure that you consult the manual before attempting to test the boat motor out of water. The manual specifies the location of the water intakes and other specifications that will be useful to your work. The manufacturer’s instructions are essential in handling any aspect of the boat.

Before flushing the motor, consult the manual for the producer’s recommendations. Flushing your motor may have similar procedures as with other boats. However, your manual has specific information on your engine that you cannot afford to overlook.

  • Never attempt to test the motor without water. Water is an essential material in this procedure. Connect a hose to the intake for water supply. Always turn on the water before starting the engine. And always put off the engine before stopping the water supply.


How is an impeller different from a propeller?

Both the impeller and propeller are important in the boat but they work in different ways. An impeller is a rotor and an essential aspect of the water pump. It is meant to pump water with force. If you use your boat in a sandy area or have it sit idle for some time, the impeller can wear out.

The propeller fan rotating and propelling the boat. The propeller is useful for thrusting the boat. Its maintenance requires cleaning routinely and keeping it away from corrosion.

Is it safe to put your boat in gear out of water?

It is not safe to put a motor in gear when it is out of water. Even if you connect the motor to muffs, it is still dangerous. The propeller has no resistance and the prop hub can get damaged.


With this guide, you should be able to test your boat’s motor out of water. When doing that, endure that you consult the user manual and always prioritize the use of water.