TECHNIQUES & BEST PRACTICES BY JOHN TIGER
OUTBOARD FLUSHING, THE RIGHT WAY
It sounds simple, but hang on! There’s a right and a wrong
way to perform this essential task
The buildup of salt in your outboard can cause blockages that result in overheating and eventual corrosion.
BACK IN THE DAY, flushing an outboard with fresh water was done only one way. A set of “ear muffs” or “flush muffs” was fitted around the engine’s gearcase to cover the water intakes, connect- ed to a garden hose with a good water supply, and the engine was run for five to 10 minutes. But today’s outboards can be flushed
using other, sometimes easier methods, without even starting the engine.
PHOTO: JOHN TIGER
Salt and brackish water is a corrosive killer of the aluminum from which outboards are made,
so flushing every time after saltwater use is a must. Left unchecked inside the cooling passages, saltwater will quickly build up and may cause cooling blockages, leading to overheating
and, over time, can corrode an engine from inside out. All outboard manufacturers recommend flushing (according to the procedures outlined in the engine owner’s manual) after
every use in salt, brackish, dirty, or polluted waters. Operating an engine in sandy, silty, or
muddy fresh water also dictates the need for periodic flushing.
THE OLD-SCHOOL WAY
Flush muffs are the most common way to flush an outboard; they’re available at most marine
stores and online resellers. They’re inexpensive, and easy to use. Connect to a garden hose,
fit the muffs over the engine’s water intakes
on the sides of the gear case, turn the water
on, start the engine, and let it run. That’s it,
with the following precautions: