Why Flushing Your Outboard Motor Matters
Salt, sand, and silt are the enemies of an outboard motor's cooling system. Every time you run your engine in saltwater or dirty water, these particles find their way inside the cooling passages. Leave them there and they cause corrosion, scaling, and blockages that overheat the engine — often at the worst possible moment. Regular flushing after every saltwater run extends engine life dramatically, and it only takes five minutes with the right tool.
Motor muffs make that five minutes effortless.
The Anchor-Man Boat Motor Muffs
The Anchor-Man Boat Motor Muffs are a dual-feed muff-style engine flusher that connects to a standard garden hose and delivers fresh water directly to your outboard or I/O sterndrive's water intakes. Available in orange and blue, they fit the vast majority of inboard and outboard engines on the market.
- Dual feed design — water enters both sides simultaneously for complete cooling system coverage
- Fits most outboard brands — Mercury, Yamaha, Evinrude, Johnson, Honda, Suzuki, Nissan, Chrysler and more
- Works for flushing AND winterising — connect to a fresh water hose for flushing, or connect to an antifreeze kit to winterise the cooling system
- Simple to use — slip over the lower unit water intakes, connect the garden hose, start the engine
- Extends engine life — removes salt, sand, sediment, seaweed, and silt from the cooling passages
How to Flush Your Outboard With Motor Muffs
- Keep the engine out of the water — motor muffs are used on land or on a trailer, not in the water
- Slip the muffs over the lower unit — position them over the water intake ports on the lower unit housing
- Connect a garden hose — attach to the hose fitting on the muffs and turn on the water fully
- Start the engine — let it run at idle for 5–10 minutes; confirm water is coming from the telltale (pilot water stream)
- Shut off engine before water — always turn the engine off before turning off the hose
- Repeat after every saltwater run — make it part of your post-launch routine
How to Winterise Your Outboard With Motor Muffs
At the end of the season, flushing alone isn't enough — any water left in the cooling passages can freeze and crack the engine block or water pump housing. To winterise:
- Flush the engine normally with fresh water first
- While the engine is still running, switch the hose to a premixed antifreeze solution and let it circulate for 2–3 minutes until pink antifreeze appears at the telltale
- Shut off the engine, then the water/antifreeze supply
- Fog the cylinder bores with storage oil through the spark plug holes or air intake (per manufacturer instructions)
- Store the engine vertically to drain any remaining water
Which Outboard Brands Are Compatible?
The Anchor-Man motor muffs fit virtually all popular outboard brands including:
- Mercury and MerCruiser
- Yamaha
- Evinrude and Johnson (OMC)
- Honda Marine
- Suzuki Marine
- Nissan Marine
- Chrysler (older engines)
If you're unsure whether the muffs fit your specific engine, check the width of the water intake grill on your lower unit — most standard units are compatible.
The Cost of Not Flushing
A new water pump impeller costs $30–$80. A corroded water jacket or cracked cylinder head costs thousands. Five minutes with a set of motor muffs after every saltwater run is among the best maintenance ROI in boating. Don't skip it.