Installing the Flush-M™ outboard flush kit is quick, simple, and requires no special tools. Once installed, Flush-M™ makes it easier and faster than ever to flush your outboard motor, helping you prevent corrosion, especially after saltwater use.
Flush-M™ permanently replaces your factory flush plug with a marine-grade quick connect outboard flush fitting, allowing you to flush your engine in seconds — without removing tight plugs or struggling with awkward fittings.
Flush-M™ Quick-connect provides the best way to flush all Mercury, Yamaha, Suzuki, and Honda 4-stroke outboards, making routine maintenance faster and more reliable.
Clean hands — no tools required
Step 1: Locate the Factory Flush Port
Find the OEM sealed flush plug on your outboard engine. This is typically located on the side or rear of the engine cowling, depending on whether you have a Mercury, Yamaha, Suzuki, or Honda 4-stroke outboard.
Step 2: Remove the OEM Flush Plug
Carefully unscrew and remove the original factory flush plug.
This plug is no longer needed once Flush-M™ is installed.
Tip: If the plug is tight, remove it slowly to avoid cross-threading.
Step 3: Install the Flush-M™ Quick Connect Fitting
Thread the Flush-M™ fitting into the flush port by hand until snug.
The integrated O-ring creates a watertight seal, preventing leaks while flushing.
✔ No adhesives✔ No sealant✔ No tools required
Step 4: Installation Complete
Flush-M™ now stays permanently installed, ready whenever you need to flush your outboard motor.
1. Remove the original OEM plug from the engine cowling.
2. Unscrew the OEM plug from the 3/4" female hose receptacle.
3. Separate the OEM plug from the lanyard by rotating it in a counterclockwise rotation until free.
4. Fit the Flush-M™ Mercury® to the lanyard and the ¾" female hose receptacle.
(For all V8 engines - install the included 90° Elbow)
5. Install the Flush-M™ Mercury® back into the engine cowling, securing it in place with a ¼ turn in a clockwise rotation.
NOTE : Remove the engine cowling to ensure there are no leaks or hose kinks upon initial flushing.
1. Remove the original OEM plug from the engine cowling.
2. Remove the cap from the Flush-M™ by twisting counter clockwise ¼ turn and pull outward.
3. Install the Flush-M™ into the cowling by rotating it in a clockwise direction until firm, using a 5/8ths wrench for added leverage if necessary.
NOTE : Do not over-tighten.
1. Separate the OEM Yamaha flush port from its base by unscrewing in a counter-clockwise direction until free.
2. Securely screw the black male quick connect into the Yamaha flush port and the black female quick release onto the Yamaha base.
3. Connect the 2 newly installed ends into one another.
