How to Use Earmuffs on an Outboardby Pauline Gill
Marine flush adapters, termed earmuffs in boating circles, allow outboard motors to receive cooling water from a garden hose whenever the motor must be run out of water. They consist of two flat opposing rubber cups, one with a hose connection, on both sides of a long U-shaped bracket that allows them to seal against both sides of the lower drive unit over the normally-submerged water intakes. The two cups on the U-bracket look like earmuffs, and thus the term. Use these earmuffs when servicing a motor.
Place the trailered or lifted boat in a spot where water can run off easily. It is best if the ground slopes down away from the rear of the boat.
Run a garden hose from the water supply spigot valve to the rear of the boat, making sure there are no kinks.
Thread the earmuffs onto the end of the garden hose as you would a hose nozzle or lawn sprinkler.
Locate the water inlet strainers or holes located on both sides of the outboard motor’s lower drive unit skeg. These are usually located on the flat section of the lower unit right above the cylindrical gear case. On many larger motors, you are able to look right through the inlet to the other side.
Slide the earmuffs gently over the front of the skeg and center the rubber cups right over the inlet. The elastic squeezing force supplied by the bracket will allow the cups to be compressed slightly to form a tight seal on the side of the skeg. Turn on the garden hose until water just starts to flow out around the cups.
Remain vigilant that the hose, pets, or children are not in the motor’s vicinity, especially near the propeller.
Start the outboard motor with the normal throttle and choking procedures you use in the water. Set the throttle to a fast idle, about 1500 rpm if you have a tachometer, with the gear disengagement feature active. This feature allows you to set the throttle to any point without engaging forward or reverse gear.
Carefully watch for the cooling water's telltale stream to start flowing from the back or side of the motor. The stream provides assurance that the water pump in the lower unit is working properly, and that the cooling passages in the engine block are full and absorbing heat from the engine.
Shut the motor down if the telltale stream is not flowing within 20 seconds. Check for blockage in the telltale stream outlet grommet. If this is blocked, the stream’s water may be running down the inside of the skeg with the exhaust. Blockage may be removed with a coat-hanger wire stuck in the grommet to a maximum of about an inch depth. If you still cannot obtain a telltale stream, the water pump impeller may be broken or worn out entirely necessitating its replacement.
Use this regimen in the following contexts to help keep your motor performing like new for many years: Every time the boat is used in salt water, when winterizing the motor, and when performing tune-ups or other maintenance on the motor that requires running it out of the water.
Store the earmuffs out of direct sunlight in a secure place aboard your outboard boat so that you can use them when boating away from home too. Many marinas have fresh water hoses to allow boat owners to flush their motors after use.
- Earmuffs work great for most stern drive units too.
- Always flush a motor for five minutes after using it in salt water.
- Don’t ever run a motor without cooling water--it could damage the water pump, or melt down the motor.
Items you will need
- Garden hose