Chris-Craft 32 Launch (RJ) Owner's Manual page 67

Engine Instruments (Continued)
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 careful helmsmen will chart boat speed vs. RPM so that, in the event of other electron-
ics 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 en-
gine. Adequate oil pressure is required to pump oil into the many highly-loaded bearings that re-
quire lubrication. Inadequate oil pressure can lead to excess wear and possibly catastrophic fail-
ure of the engine. Check the manufacturer's engine manual to determine normal oil pressure for
the engines in your boat. Do not operate an engine that has had a loss of oil pressure.
Engine Temperature Gauge
The engine temperature gauge indicates the temperature of the water 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. 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 temperature.
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 en-
gines running a charging voltage of 13 to 15 volts should be indicated. Low voltage with the en-
gines running (less than 12 volts) indicates a possible problem with the charging circuit. The en-
gines are unlikely to start with less than 12 volts indicated on the volt meters.
Fuel Gauge
The fuel gauge indicates the fuel level in the tank. Due to the irregular shape of the fuel tank and
the angle of the tanks when running, indicated fuel level does not correspond directly with the
ratio of remaining fuel to total fuel capacity (i.e. an indicated fuel level of 1/2 does not indicate 1/2
the capacity of the tank is remaining, but indicates the level of the fuel is 1/2 the height of the
tank at the sender). Remember, not all fuel capacity is usable capacity. Careful planning of long
trips using a safety reserve is advised. It is always prudent to fill the tanks completely after each
use to prevent condensation within the tanks.
Engine Hour Meter
The engine hour meter is actually located on the engine itself and indicates the total cumulative
time in hours of operation. The engine hours should be noted on the engine log for all oil
changes, filter changes, scheduled and unscheduled maintenance. An accurate and carefully
maintained engine log is a valuable tool when diagnosing problems, when seeking warranty
compensation from the engine manufacturer and when your boat is re-sold.
3-5
Systems
3-5