Outboard engines and Undrowning

It's all too easy to drop outboard motors overboard. That fact is recognised by the manufacturers, who usually include a section dealing with `immersion' in their manuals.

Unfortunately, they rarely say more than take it to your nearest authorised dealer, or words to that effect - which isn't terribly useful if the disaster has struck on the Friday of a bank holiday weekend, or in a remote anchorage.

Fortunately, most small outboards that are modern enough to have electronic ignition systems respond well to simple first aid treatment.

For engines that have been dropped overboard while actually running, the best treatment is to leave the engine fully immersed - in fresh water if possible but in sea water if not - until you can get it to a professional.

Outboard motors and corrosion

Immediate action is essential: once an engine that has been immersed in salt water is exposed to the air, corrosion begins almost at once and if it is not running within a few hours (not a day or two!) it may never go again.

1 Remove the cowl, spark plug(s), air filter, and recoil starter mechanism.

2 Flush the ignition electrics with fresh water, directed through the holes in the flywheel and under its rim. You cannot make the engine any wetter than it is, so do not be afraid to use plenty of water to flush away the salt. If possible, use a hose pipe, other

wise use something like a washing up liquid bottle to produce a good penetrating jet.

3 Separate any obvious electrical connections, making sure that they are colourcoded and making a note of what goes where, and then flush those too. Pay particular attention to the spark plug cap.

4 Lay the engine down so that the spark plug holes are uppermost, and pour water into the cylinders while slowly turning the flywheel to flush the salt water out of the cylinder, transfer port, crankcase, and carburettor.

5 Turn the engine over so that the carburettor is uppermost, and pour water down the carburettor throat, to flush it through the other way.

6 Use rags to dry the engine as best you can, and then spray the ignition system liberally with a water-displacing oil such as WD40, Duck Oil, or TS10. Spray the electrical connections, too, and reconnect all except the stop switch and kill-cord switch. (They will almost certainly have `shorted out' and will stop the engine working if they are connected.)

7 Refit the recoil starter, mount the engine in its usual running position, and pull the

starter briskly and repeatedly until no more water sprays out of the spark plug hole(s).

8 Spray water repellent oil into the cylinder through the spark plug hole and into the crankcase through the carburettor, turning the engine with the starter as you do so.

9 Clean and dry the spark plug, and check that there is a spark by attaching the plug lead, resting or clamping the plug on a bare metal part of the engine, and then pulling the starter while looking and listening for the spark. If there is no spark, check the electrical connections, and make sure you have not reconnected the stop switch or kill switch.

10 Unscrew the drain plug from the carburettor float chamber, or improvise by removing the float chamber bowl, and then pump fuel through the system by squeezing the primer bulb if it has a remote tank or by spinning the crankshaft with the starter. Have a container ready to catch any fuel that comes out. Then close the drain plug or re-fit the float bowl.

11 Clean and dry the spark plug and re-fit it. Attach the plug lead, and re-fit the air filter. Give the engine full throttle and choke, and try to start the engine.

12 The chances are that more water will be driven out of the crankcase into the cylinder, so that after a few pulls it will become more difficult to spin the engine. If so, remove within an hour, if possible using a richer than usual

the spark plug and pull the starter cord a few more times to expel the water from the cylinder.     

13 Repeat stages 11 and 12 until the engine starts. Then run it under load for at least an hour.