Post-Flushing Treatment

Just as you should always keep the external metal parts of your outboard sprayed with a corrosion protection such as lanolin, you should also treat the internal metal water galleries of your outboard.

Flushing your outboard with plenty of fresh for at least 10 minutes when you return from salt water use is a very important step but I have found that it may not be enough.

I am regularly seeing outboard engines of all manufacturers (some worse than others) that are getting hot and when I dismantle them I find lots of salt build up restricting the water galleries. This salt build up goes on to corrode the metal and I have seen otherwise very good outboards of less than 10 years old become too expensive to repair. This seems to be more prevalent in four strokes.

I have always been very sceptical of so called “Snake-oil treatments” in the past and believed that fresh water flushing is all that is required. When inspecting internal water galleries of outboard engines that have been using a post flush treatment such as MACS (Marine Anti- Corrosion System) or Salt-away I have been very impressed with what I see with little to no salt build up or corrosion present.

These non-toxic products are applied to the internal water galleries through an attachment that connects to the outboard flushers. Be aware that some flush treatments are not as environmentally friendly as others.

Fill the canister with the recommended amount of product for your outboard. Some applicators have a valve that allows you to just turn it from flush to treat. The applicator without the valve can be used with the screw on canister disconnected while flushing until ready for treatment.

Flush your outboard as normal but with the special applicator connected to your flushers. Run the outboard until it is fully warmed up and the thermostat is open. Open the neutral throttle slightly to increase the engine running speed. This will increase the amount of combustion events as well as increase the water flow from the water pump to give a better flush for the thermostat.

Once the outboard is fully warmed up and while the outboard is still running turn the valve on the applicator to “treat” or screw the canister onto the applicator. Allow the outboard to run until the product has fully distributed throughout the water galleries. You will notice the water coming from the tell-tale start to feel slippery and bubbles appear in the water on the ground under the outboard.

At this stage you should turn off the outboard. The internal water galleries of your outboard are now coated with an anti-corrosion protective layer.

Do not keep running the engine as this will just dilute the product and eventually flush out all of the treatment. The diluted product that is still left in the canister can be put into a spray bottle and sprayed onto areas such as the power trim unit and steering tongue or your trailer. Some brands are also suitable for use on fishing gear.

During your next service your outboard mechanic can show you the condition of your water galleries and advise you if you are flushing correctly and make adjustments to your procedure if required.

- Contact Cairns Outboard Service for your outboard service requirements.

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