EXCESSIVE CONSUMPTION OF LUBE
OIL, FUEL, OR WATER
You should suspect engine trouble whenever
excessive consumption of any of the essential liquids
occurs. The possible troubles indicated by excessive
consumption will depend on the system in question.
Leakage, however, is one trouble that may be common
to all. Before you start any disassembly, check for leaks
in the system in which excessive consumption occurs.
The troubleshooting procedures used for a marine
gasoline engine are, in many ways, similar to those for
a diesel engine. The two types of engines are quite
similar with two exceptions, the manner of getting fuel
and air into the cylinders and the method of ignition.
This section deals primarily with the systems that
differ in the gasoline and diesel engines. In addition,
troubleshooting information is given on the electrical
Even though most electrical maintenance and repair
is the responsibility of an Electricians Mate, you, as an
Engineman, can reduce the amount of electrical troubles
by following the correct operating procedures. Most
electrical system troubles develop from improper use,
care, or maintenance.
The following information will help you detect
electrical troubles and take corrective action.
When a gasoline engine fails to start, one of three
conditions exists. The engine is not free to turn, the
starter does not crank the engine, or the engine cranks
but does not start. Figure 3-44 lists many of the
conditions and sources of such difficulties,
If the engine will not turn over, some part is
probably seized In this case you should make a through
inspection, which may necessarily include some
STARTER DOES NOT RUN
If the starter fails to turn, the trouble can usually be
traced to the battery, connections, switch, or starter
Symptoms of battery trouble generally occur before
the charge gets too low to perform the required work
Battery failure is normally preceded by a gradual decline
in the strength of the battery charge. A dead battery may
be the result of insufficient charging, damaged plates, or
improper starting technique.
The generator, used to maintain the charge of the
starting battery, may become defective. The normal
symptoms are a low battery charge when the engine is
started and a zero or low ammeter reading when the
engine is running.
The battery must be in good condition to ensure the
proper operation of the ignition system. A starter draws
a heavy current from the best of batteries. When the
battery is weak, it will be unable to operate the ignition
system satisfactorily for starting because the heavy
starting current will drop the voltage to an extremely low
NOTE: Keep flames and sparks of all kinds away
from the vicinity of storage batteries. A certain amount
of hydrogen gas is given off from a battery at all times.
In confined spaces this gas can form a dangerous
When you use tools around a battery, be careful not
to short circuit the battery terminals. Never use a tool or
metal object to make a so-called test of a storage battery.
Keep batteries in exposed locations subject to low
temperatures fully charged during cold weather. In
extreme cold weather, remove storage batteries and
place them in a warm compartment, if possible.
Electrical connections are another possible source
of trouble if the starter does not turn. All connections
must be tight and free from corrosion to provide
maximum voltage and amperage from the battery.
Battery terminals, since they are more vulnerable to
corrosion, looseness, and burning, are the principal
sources of trouble.
Burned battery terminals may be caused by a loose
connection, a corroded terminal, or a short circuit.
Burning of terminals usually occurs when an engine is
being started Burning may be indicated by such things
as smoke, a flash, or a spattering of molten metal in the
vicinity of the battery. Usually, the starting motor will
cease to turn after these symptoms appear.
Switches, electrical relays, or contactors that are
defective or inoperative may be the reason a starter will
not turn. Contactors, being subject to extremely high
current, must be maintained in the best possible
condition. Starting contactors are either manually or
magnetically operated and are designed to be operated
for only short periods of time.