L_B_2015_04_

Fueling Success

Get pumped to learn the proper way of changing a fuel fi lter.

O

ne of the most common reasons for towing service

calls is — you probably guessed it — fuel problems.

Obviously, you need to make certain that you have enough

fuel on board before leaving the dock en route to your next

great on-water adventure. But how can you be sure the fuel

you have in the tank is in good condition?

Unlike a car, where you most likely fill up at least once

a week, fuel on a boat can sit in the tank for months, if not

years. As fuel sloshes around in there, it picks up all sorts

of dirt and debris that’s lurking on the tank’s bottom. This

bottom-dwelling gunk mixes with the fuel and winds up

being carried through to the engine, where it can put the

kibosh on your weekend faster than you can blink an eye.

Fuel filters play a vital role in keeping these contaminates out of

your engine, and it pays to change these often. In my experience,

filters often are forgotten; but they should be changed at least

once per year at a minimum, and at every engine service interval.

On all but the very smallest of engines, there will be two

filters: One in the fuel line between the tank and the motor,

and a smaller filter attached to the engine itself. The filter

in the fuel line will be the larger of the two, and its purpose

is to catch and retain the dirt, water and bacterial growth;

the smaller engine filter gobbles up any remaining dirt that

managed to get by the first, ensuring that only clean, pure

fuel reaches the engine.

Changing a gasoline fuel filter

On my boat, I have a small collection of engine spares that

I take with me for the main engine, generator and dinghy

outboard. Included in this kit are several filters, and these

have saved the day for me on more than one occasion, when

I unknowingly purchased some poor-quality fuel.

Changing a fuel filter is seen by many as a black art,

but it’s actually pretty simple. Although the design and

layout of fuel systems vary by manufacturer, the principles

are identical in almost every instance. Here’s how to do it:

1. For a gasoline engine, make sure that the engine is
   turned off and the key is removed from the ignition, so
   that it cannot accidentally be started.


2. Turn off the fuel using the fuel petcock, which will be
   installed either at the fuel tank or on either side of the
   filter. Doing so will ensure that fuel does not drain from
   the tank while you have the filter removed.


3. Place a small bucket or oil absorbent pads underneath
   the filter to catch any fuel that may spill. Some filters
   have a drain in the bottom, which makes things easier,
   as excess fuel can be drained into a container before the
   filter is removed.


4. Unscrew the filter; this may only be hand-tight, but it’s
   possible you’ll need a filter wrench if it’s really tightened
   down.


5. Keep the filter upright, as it will be full of fuel, then
   place it in a Ziploc bag for proper disposal.


6. Screw on the new filter, and after turning the fuel back
   on squeeze the priming bulb to refill the fuel line with
   gasoline.


7. After carefully checking for leaks, run the bilge blower
   for 5 minutes to evacuate any explosive fumes.


8. Start the engine and once again check for leaking.

Changing a diesel fuel filter

Changing a fuel filter on a diesel engine is a little more

complicated, but not much, as there are a couple of extra

steps. Bleeding air out of the fuel lines is an additional task

with diesels, as trapped air will prevent the engine from

starting — although there are many diesel engines nowadays

that are self-bleeding. If that’s the case with your diesel,

then changing the fuel filter is as simple as the gas engine

procedure outlined above.

If you have one of the more traditional diesel engines,

then the process for purging air will be highlighted in the

engine owner’s manual. It’s wise to familiarize yourself with

the proper procedures — before you may need to change

filters in a hurry! ★ PHOTO BY MARK CORKE

Mark Corke is an

accomplished journalist,

author and sailor. He’s the

creator of the popular blog

onboardwithmarkcorke.com,

which focuses on various DIY

boating projects.

by Mark Corke

CORKE BOARD

Keeping your boat’s fuel

fi lters changed and in good

working condition is key to

helping reduce the potential

for on-water problems

this spring and summer.

Fuel quality is nearly

impossible to determine at

the pump, so do your best

to maintain the integrity of

your boat’s tank by ensuring

fi lters are removing pesky

contaminents.

20 APRIL 2015 | LAKELANDBOATING.COM

Corke_APR15.indd 20 3/2/15 3:41 PM