Draining a boat motor while operating an outboard is a routine maintenance task. Running the engine without a water source for an extended period of time will cause damage, so you will need to connect a hose to the engine's water inlets. Some newer engines have built-in fittings that accept hose nozzles. If your engine does not have them, you will need a Flusher boat engine kit with sleeves. Turn on the water before starting the engine, and then run it for 5-10 minutes or according to the manufacturer's recommendations.
Steps
Part 1 of 3: Connecting a Hose and a Flusher Boat Engine with Sleeves

Step 1. Read the manual before starting the outboard motor
Check the manual to find out where the inlets are located and if they have built-in hose connections. If not, you will need an engine kit with sleeves.
Most of the manufacturer's recommendations for draining or running an outboard motor are similar. However, you still need to review the specific procedure for your model

Step 2. Screw the hose directly onto the motor if it has a built-in connection
With the engine in an upright position (not tilted in the trailer position), locate the water inlets on the sides of the lower unit. Screw the hose nozzle into one of the inlets. The manual will likely recommend covering the other entrance with heavy duty tape.

Step 3. Purchase a sleeved boat motor at a boat store or online
If you need a sleeved boat motor, you can purchase a set for less than $ 10 at a marina, sporting goods store, or online. They look like earmuffs connected by a long V-shaped rod.

Step 4. Wet the cuffs for a better seal
Many boat owners splash the inside of the hoses with water before connecting them to the motor. A better seal can help prevent these from slipping while the engine is running.

Step 5. Attach the sleeves to the engine and keep them away from the propeller
Slide them into the lower motor unit so they line up over the water inlets. Make sure to position the sleeves so that the connecting rod is facing the engine on the opposite side of the propeller.
While you should keep the engine in neutral while it's running out of the water, you still need to be careful with the propeller. If the motor accidentally slips into the gear and the connecting rod is on the propeller side of the motor, injury or damage will result

Step 6. Screw the hose onto the sleeves
One of the sleeves has a nozzle and the other is solid. Find the one with the nozzle, then twist the hose on it. Double check that the connection is tight and that the hoses fit snugly over the engine's water inlets.
Part 2 of 3: Starting the Engine

Step 1. Open the water flow
After connecting the hose, go to the tap and turn on the water. Check the manual to see if it specifies a water pressure setting. Many manufacturers recommend setting it to medium pressure.
Do not start the engine before opening the water supply

Step 2. Place the engine in neutral
Make sure the gear lever or throttle is in a neutral position. The engine must be in neutral to start and must remain in neutral while you run it.
If you need to start the engine to test propeller function, be careful to make sure no people or objects are near the propeller in motion

Step 3. Start the engine
Depending on the type of engine, insert the key or pull the starter to activate the engine. For some electric motors, you will also have to press and release a button after turning the key.

Step 4. Make sure the engine water pump is running
You should see a stream of water coming out of the top of the engine. If there is no overflow, there is something wrong with the water pump.
If there is no flow, shut off the engine immediately. Feed a thin wire into the outlet tube to check for debris. Start the engine again to see if that fixed the problem. If there is still no outlet, you will likely need a mechanic to replace the water pump
Part 3 of 3: Drain the engine

Step 1. Run the engine for 10 minutes, or according to the instructions in the manual
If you are going to drain the engine, most manufacturers recommend running it for 5 to 10 minutes. If you are going to make it work for another purpose, such as testing its function, do it for as long as the maintenance task requires.
- Do not run the engine unattended. Keep an eye on the hoses and make sure they don't slip out of the water inlets.
- Regardless of the task, you are unlikely to need it to run for more than 10-15 minutes.

Step 2. Turn off the engine before shutting off the water
After about 10 minutes, turn the key or close the throttle to turn off the engine. Turn off the water only after switching off the motor. Running the engine without a water source for just a moment could cause damage.

Step 3. Unscrew the hose from the sleeves or built-in fittings
After shutting off the water, remove the hose from the hoses or from the engine water inlet, roll it up and store it.

Step 4. Remove the cuffs if you are using them
If necessary, slide the sleeves off the lower motor unit. Store them in a boathouse, garage, or other practical place so you can drain the engine after your next outing.

Step 5. Let the water drain before tilting the engine
Keep the engine low for 30 to 60 minutes to allow the water to drain from the car. After letting it drain, lift the engine into an inclined position. Cover the boat and tow it to your garage or boathouse, or store it however you like.