Built In Flushing Attachment

Good Points - Quiet and simple
Can be used on outboards while still in the water
Is used without having to run the engine

Bad Points - Does not flush under the water pump
Does not flush the thermostat area thoroughly
Does not flush the gearcase exhaust cavity
Does not flush the water galleries in the sump of most 4 stroke outboards

This type of flushing attachment allows moored vessels kept in the water to flush the salt water from the water galleries; or to give a trailered outboard a flush when the noise of the outboard running is a problem.

It does not provide adequate fresh water flushing to the water pump or through the water tube, thermostats and oil sump in some cases.

On some outboards, this attachment is part of the engine undercase and will harbour salt water which can potentially cause serious corrosion over the long term if it is not used.

If you have a fresh water flush attachment, it needs to be flushed out every time the outboard is used in salt water, and treated with a post flush water gallery treatment to avoid build-up of salt in this area. This is in addition to your normal flushing regimen.


There may be a fresh water flushing attachment built into your outboard.

Connect a hose to the attachment and turn on the hose.

Most outboards should not be run with this type of flushing attachment, as it does not provide adequate water to the under-side of the water pump. Any outboard operated on the flush attachment should not be operated above idle.
Apply post flush water gallery treatment to this section also.
Check owners manual to determine whether your outboard can be run using a flushing attachment.

- Contact Cairns Outboard Service for your outboard service requirements.

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