Changing Your Boat's Oil
by Tim Harrington, Madison Marine and
Boat Maintenance Specialist
Think about your boat as an investment. The
investment you make upon purchase comes with many hidden costs to keep
your boat running. Boat owners know what it takes to keep their boats
in running condition and what marina and maintenance costs can be. As
a boat repairman specialist, I see many repetitious problems that if
left unattended, turn into major repair bills. A boat is not like a
car it needs more attention.
The biggest key to success is your maintenance
program, which as the boat owner you control. Water is a very harsh
environment, especially salt water, and even though you may always be
in fresh water, your maintenance program should not deviate, fresh
water is just a little more forgiving. By keeping up with maintenance
that you are capable of doing yourself, you will see at least two
benefits over the course of a few years. Breakdowns will be kept to a
minimum (remember, your boat seldom breaks down at a dock), and you
get to keep more of your hard earned money.
This article discusses lubricant or oil, and how
to change it in most inboard gas engines and I/Os. This may be one of
the most significant things you can do to increase the life of your
engine. I do my maintenance schedules based on use and manufacturer
recommendations. This is usually done by hours or break-in time if
your boat is purchased new. If you are a new boat owner, keep to your
warranty times to protect your new purchase. To maintain your
equipment, stay ahead of your pre-scheduled maintenance and inform
your dealership well in advance of your intention to bring your boat
in. This will give your dealership time to perform the work and keep
your boat out-of-the-water time to a minimum. For older boats, there
are manuals for just about everything that will act as a guide for the
owner. Another source of information is the "tech-pub" (technical
publication) for the maintenance you intend to perform yourself.
On with the oil change! Most procedures to do
this are quite easy and will help in the longevity of your boat. Most
gas inboards or I/Os will take anywhere from 4.0 to 7.0 quarts of oil
and in some cases more. Check on the capacity of your engine from the
owner's manual or tech pub.
To begin the oil change process, start your
engine and let it warm up for 5 minutes or more. Shut your engine down
and remove the keys from the ignition. What you have just done is to
thin out the viscosity of the oil to make it easier to siphon your
oil. Also prior to this you should have checked to make sure you have
the correct oil filters for your engine.
Now that you are ready to remove the oil, you
need to use some sort of siphon. There are many different kinds of
equipment to do this, ranging in price from $25 to over $200. These
can be found at
www.americanboating.org/products.asp. The difference in price is
that some are manual and some are electric, working off of 12-volt DC
current on the boat. I use a hand siphon for most boats up to 35 feet.
If you elect to use an electric pump and it operates in a pump and
siphon modes, check the mode prior to siphoning! Most electric pumps
are attached to a 5-gallon bucket and if old oil or residue is left in
the bucket, and you are in the wrong mode, you will introduce it into
The next step is to use CLEAN rags or preferably
diapers placing them in the bilge beneath the engine. This is for two
reasons - one is to absorb any moisture in the bilge, and second is to
catch any oil that may make its way to the bilge. The next step is to
siphon the oil out. This is done in most instances by running the
provided tube down your dipstick access. You have warmed the oil so
most of the oil should be drawn out of the block area, plus while you
were prepping to do this; your oil should have drained down to this
level. Once this has been done take your oil and place it where you
will not be in danger of knocking it over.
Now remove the oil filter. This is where you may
have some overflow of oil. This is one of the reasons for the diapers
and it helps to have a small plastic container that is larger than the
oil filter to catch the overflow and to put the filter in. Now that
you have removed the filter, it is time to put the new one on. Take a
finger and put a little oil on the gasket side of your filter. Once
done, spin the filter back on, being careful not to cross thread the
filter. TIGHTEN by hand until snug making sure contact is tight.
As I said earlier, not all engines take the same
amount of oil. If the engine I am servicing takes 7 quarts of oil, I
would at this time put in 6.5 in. The oil filler cap usually on the
valve cover and will likely show the type of oil that you should use.
At this point I start cleaning up and date my filter and if the boat
has an hour meter the hobs time on the filter for maintenance tracking
and initial it.
Now it's time to turn the key and cycle the
lubricant through the system. While doing this, watch your temp and
oil pressure. If there is a problem, shut the engine down and check to
make sure everything is tight and nothing is leaking. If there are no
problems, shut the engine down and wait 5-10 min. and check the
dipstick for the oil level. Adjust the quantity to maintain the full
line. Do not overfill.
The job should be coming to a close. Pick up the diapers that were
put in the bilge. Try to clean the bilge at the same time that you are
picking up. The reason for doing this is so you can do a visual check
for potential problems before you leave the dock. It is always easier
to fix something before it becomes a problem! Checking the belts for
corrosion while you are right there is a good idea.