Running an Outboard Motor Dry: What You Need to Know

One of the most important rules of outboard ownership is to never start your motor out of the water without a dedicated cooling water supply. A true “dry start,” even for a few seconds, can cause serious damage to your engine’s water pump.

However, there are many valid reasons to run your motor on land, such as routine maintenance and winterization. The key is knowing how to do it safely. This guide explains the risks of an improper dry start and walks you through the correct methods for running your outboard motor out of the water.

The Danger: Why You Should Never “Dry Start” Your Outboard

At the heart of your outboard’s cooling system is a rubber water pump impeller. Its job is to draw in water and circulate it through the engine to prevent overheating. Water is not only a coolant; it is also the impeller’s only lubricant.

When you start an outboard without water, the dry rubber impeller spins against its metal housing. Within seconds, the friction generates intense heat, causing the rubber to shred, melt, and fail completely. This can lead to expensive repairs and, if unnoticed, a severely overheated engine the next time you’re on the water.

The Right Way: How to Run Your Outboard Motor on Land

To run your motor safely on land, you must provide a continuous supply of cooling water. The most common way to do this is with a motor flusher, often called “earmuffs.”

Using “Earmuffs” (Motor Flushers)

This simple accessory is essential for every outboard owner. It connects a standard garden hose to your motor’s water intakes.

1. Locate the Water Intakes: Find the water intake screens on both sides of the gearcase (the lower unit).
2. Position the Earmuffs: Slide the motor flusher over the gearcase, ensuring the rubber cups completely cover the intake screens.
3. Connect and Turn On Water: Attach your garden hose to the flusher. Turn the water on to a strong, steady flow. You should see water leaking slightly around the cups.
4. Start the Engine: With water flowing, you can now safely start your engine.
5. Check for Water Output: Immediately look for the “telltale” stream of water coming from the outboard’s pilot water outlet. This confirms that water is circulating correctly through the engine. If you don't see a stream within 10-15 seconds, shut the engine off immediately.
6. Engine Off First: When you're finished, turn the engine off first.
7. Turn Off Water: After the engine is off, you can turn off the hose.

Common Reasons to Run Your Motor on Land

Running your motor with a flusher is a key part of responsible ownership. Common reasons include:

• Flushing After Saltwater Use: This is crucial to prevent internal corrosion. For more information, read our guide on Saltwater Boating: Protecting Your Outboard Motor from Corrosion.
• Winterization: Running the engine is necessary to circulate fogging oil and stabilize the fuel system.
• Diagnostics: Safely running the engine on land helps when troubleshooting issues, like those found in our Outboard Motor Bogging Down Guide.
• General Maintenance: Warming up the engine oil before a change.

Knowing how to run an outboard motor out of water the right way is an essential skill for any boater. By consistently using a motor flusher or test tank and following the correct steps, you can perform critical maintenance without risking damage. A few minutes of proper procedure can save you from costly repairs and ensure your motor is ready for your next trip.

For the right maintenance kits, motor flushers, and expert advice, OnlineOutboards.com is here to help.