Engine Instruments - Chris-Craft 2015 21 Carina Owner's Manual

Systems

Engine Instruments

You should become familiar with "normal" gauge readings for your engines and become accustomed to
scanning the instruments when running. Unusual instrument readings will require immediate attention.
Do not ignore unusually high or low instrument readings. Shut down the engine and have the problem
diagnosed before operating the engine.
Tachometer
The tachometer indicates the revolutions per minute (RPM) of the engine. Important RPM's to note
from the manufacturer's engine manual include idle RPM, normal cruise RPM and maximum RPM.
The maximum RPM should not be exceeded. Although tachometers do not indicate boat speed, a care-
ful helmsmen will chart boat speed vs. RPM so that, in the event of other electronics problems, he will
have a very good idea of boat speed from his tachometers. A sudden change of RPM may indicate a
problem within the engine or a problem with the drive train or running gear. Do not ignore
"unexplainable" changes in RPM. A simple check of the engine and running gear may prevent costly
repairs.
Speedometer
Read in miles and kilometers per hour. Indicates speed of the boat.
Oil Pressure Gauge
The oil pressure gauge measures the pressure of the lubricating oil circulating through the engine.
Adequate oil pressure is required to pump oil into the many highly-loaded bearings that require lubrica-
tion. Inadequate oil pressure can lead to excess wear and possibly catastrophic failure of the engine.
Check the manufacturer's engine manual to determine normal oil pressure for the engines in your boat.
Shut down and do not operate an engine that has had a loss of oil pressure.
Water Temperature Gauge
The water temperature gauge indicates the temperature of the coolant mixture circulating inside the en-
gines cooling circuit. The engine is equipped with a thermostat that controls flow of coolant within the
engine thus maintaining correct operating temperature. Engine coolant temperature is not affected by
seawater temperature. Correct operating coolant temperature indications for your engine may be found
in the engine manufacturer's manual. An unusual change in temperature may indicate problems with the
raw water circuit or internal engine problems causing excess heat. Shut down and do not operate an
engine that is indicating coolant temperature in excess of the manufacturer's maximum allowable tem-
perature.
Voltmeter
The voltmeter monitors the voltage of the battery and the charging circuit of the engine. Normal voltage
for a fully charged battery with the engines shut down is about 12.8 volts. With the engines running a
charging voltage of 13 to 15 volts should be indicated. Low voltage with the engines running (less than
12 volts) indicates a possible problem with the charging circuit. The engines are unlikely to start with
less than 12 volts indicated on the volt meters.
3-21 3-21