MOBILE OUTBOARD MECHANIC

What should I do with a submerged outboard?

- Time is very important. The corrosion process starts as soon as the outboard is taken from the water -

If you can’t get the engine going within less than 2 hours it should be taken to an experienced outboard mechanic immediately or dismantled and protective oil applied to all internal components.

If your outboard was submerged while it was running it is likely that it is seriously damaged with possible bent con rods and twisted crankshaft. Remove the spark plugs and check if the engine turns over easily if it is hard to turn over it will have to be dismantled and inspected immediately.

If your outboard is a 4 stroke and it is submerged in salt water, the engine will have to be completely dismantled because the salt water causes corrosion to the internal components.

Do not attempt to start or turn over the engine yet.

Wash away any salt, sand or mud from the outboard including the carburettors, flywheel and electrical components.

Remove the air box from in front of the carburettor if the outboard has an air box.

If sand or mud is in the inside of the engine, do not attempt to start or turn over the engine. It will have to be dismantled and cleaned. Get the outboard to an experienced outboard mechanic immediately. If you can’t take the outboard to a mechanic immediately or dismantle it immediately completely re-submerge the engine part of the outboard into fresh water. The corrosion process will be restricted when the outboard is back under water.

If there is no sand in the inside of the engine or carburettor or under the flywheel, remove all of the spark plugs and get out as much salt water as possible by turning over the engine.

Direct copious amounts of fresh water into the throat of each carburettor and slowly wind the engine over by hand while holding the throttle shutters fully open.

Direct copious amounts of fresh water into each of the spark plug holes and slowly turn the engine over by hand.

If possible, place the outboard on the ground with the spark plug holes facing down. This is by far the best method but if this is not possible you will require squeeze bottles to squirt oil and methylated spirits into the carburettor throats.

Continue doing this until you are sure all the salt water is gone.

Remove as much of the fresh water as possible by turning the engine over the same way.

On a four stroke engine drain and refill the engine oil and replace the oil filter.

DANGER! METHYLATED SPIRITS IS FLAMMABLE. DISABLE SPARK BEFORE USING METHYLATED SPIRITS.
The spark can be disabled by activating the stop switch or by disconnecting the stator.
If you are not fully confident that you have disabled the spark you should skip the next step.


Methylated spirits will absorb some of the fresh water that is still inside the engine.

Pour methylated spirits into each of the carburettor throats and turn the engine over by hand. The methylated spirits will travel through the inside of the engine and come out of the spark plug holes. The methylated spirits will look creamy while it is still absorbing water. When the water is removed the methylated spirits will start coming out clear.

Pour engine oil down the throat of each of the carburettors and turn the engine over by hand fast enough to distribute the oil throughout the inside of the engine. This will lubricate the crankshaft, con-rods and bearings of 2 strokes and lubricate the valve stems and throttle shutters of 4 strokes. The faster the engine turns over, the more thorough the oil distribution. Don’t skimp here, use plenty of oil. If your normal engine oil is not available, any oil will do. Once this is done thoroughly, all of the expensive internal components are protected.

Place the outboard in an upright position.

Remove the fuel inlet hose from the carburettor and flush good fuel through all of the hoses to ensure no water is being pumped back into the carburettors. Then reconnect the fuel hose to the carburettors.

Remove the drain bung from the bottom of the carburettors and flush good fuel through the carburettors until all the water is out of the carburettors. The water is a lot thicker than the fuel and will look lumpy.

Repeat this for all carburettors until the fuel comes through clean.

Clean and refit all spark plugs.

Dry all wiring and electrical components using compressed air or a dewatering spray such as CRC.

Attempt to start the engine using good 2 stroke fuel. The fuel should be mixed at double oil.
Use straight fuel for 4 strokes.

It may be very difficult to start and may take many attempts.

If the engine starts it should be run for a long period to ensure all of the water is gone.

If the engine does not start, try to find out why and fix the problem. It is best if the engine is started as soon as possible.

If you can’t get the engine going within less than 2 hours, it should be taken to an experienced outboard mechanic immediately or dismantled and protective oil applied to all internal components.

Electric start and oil injected outboards require further maintenance.

The starter motor should be removed, dismantled and cleaned immediately or placed in a bucket of water if unable to disassemble immediately.

The carburettors should be removed, stripped and cleaned as soon as possible to ensure small pockets of salt do not corrode important sections inside the carburettors.

Electric start outboards may have corroded battery lead terminals and damaged solenoids and batteries which will normally all require replacement.

- Contact Cairns Outboard Service for your outboard service requirements.

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