Keeping your fuel clean

by Lee Mylchreest on 8 Jan 2013 When you move out of home waters, one of the dangers of cruising is ending up with dirty fuel which clogs and stops your engine. Here we talk about some of the solutions:

One of the greatest dangers is complacency. Sailing in home waters, you get used to checking your fuel filter at a certain rate, which may not be appropriate if the fuel comes from a different source. And don't be by the idea that just because you are in a so-called 'Western' country that you can't get dirty fuel. Stories abound of cruising sailors who inadvertently received a dose of dirty fuel when it was delivered that way to the reseller from the refinery.

Routinely replacing your fuel filter is relatively simple and ensures that contaminates can't reach your engine's fuel injectors and other sensitive parts in the fuel system, but there's something else. Many long range cruisers usually use not one, but two fuel filters, to ensure that, if there is small contamination, it is caught before it spoils your day or your entire voyage.

So the key to proper fuel filtration is to approach it in a sequential fashion, a process known as multistep filtration.

The best advice is that you should use two filters of sequentially finer filtration. The first, or primary, filter should have about a 10-micron rating. The specification of the secondary filter typically carries a 2-micron rating.

This, of course, means that you must carry spare filters of two types, and the checking and cleaning processes are doubled. However, if you have ever been caught out with engine problems because of dirty fuel, you will think the process well worth while.

The other desirable, when taking fuel from a suspect source, and sometimes when you leave home waters this is unavoidable, is to filter the fuel as it goes INTO boat. This can provide difficulties, particularly if the fuel source is used to catering for large ships, and the flow is very strong.

There is one filter known as a Baja (pronounced Baha) filter, which is reputed to be excellent by those who have used them for years. There is also one easily available from your local marine store or West Marine, which is less expensive and seems, by reports, to work just as well. It is a teflon-coated, stainless-steel filter which separates water and dirt from gasoline, diesel and kerosene fuels.

It is made from industrial standard electroconductive polypropylene that can be grounded for extra safety. Fuel flows through the filter into the tank and water and sediment stay in the funnel.

Whether you actually need these precautions depends greatly on where you sail, but keeping your engine working at all times is vital to happy cruising, and, in taking the chance by NOT filtering, you might see your engine gasp and die just when you most need it.