Generac Power Systems GTH760, Service Manual

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deSCrIPTIoN
The Generac GTH/GTV-760/990 OHVI V-twins use a full pres-
sure lubrication system with an oil filter. The gerotor type oil
pump draws oil from a screened oil pickup in the sump and
pumps oil through the oil filter.
The filtered oil flows through an oil gallery in the sump and
is distributed to the main bearings, connecting rod bearings
and camshaft bearings. Engine oil pressure will vary with oil
viscosity, ambient air temperature differences, operating tem-
peratures and engine load. Follow the oil recommendation on
page 8-2 of this section.
oil Pressure - @ 70° F (21 ° C):
15 - 50 psi (1.0 - 3.5 bar)
Two pressure relief valves limit the maximum oil pressure in
the system to 60 and 40 psi respectively.
ProTeCTIoN SYSTeMS
LOW OIL PRESSURE SWITCH:
The engine is equipped with a low oil pressure switch that
closes the circuit between the terminals when the oil pressure
drops below 8 psi. If one terminal is connected to the ignition
ground wire and the other terminal is connected to ground, the
engine will shut down on low oil pressure. The switch can also
be connected to an alarm or light to indicate low oil pressure,
instead of shutting down the engine.
A delay built into the shutdown system on some engine appli-
cations allows oil pressure to build during starting. The delay
allows the engine to run for about 10 seconds before sensing
oil pressure. If the engine is wired for low oil pressure shutdown
and the system senses low oil pressure during operation, the
engine shuts down. The engine will not continue to run until
8 psi of oil pressure is reached. If you try to restart the engine
within (five) 5 seconds after it shuts down, the engine may
NOT start. The system needs 10 seconds to reset.
NOTE: Some differences may exist between low oil pres-
sure systems. Refer to the electrical schematic/wiring
diagram in the Owner’s Manual for the specific applica-
tion using this engine.
HIGH TEMPERATuRE SWITCH (OPTIONAL):
This switch’s contacts close if the temperature should exceed
approximately 140º C (284º F), initiating an engine shutdown.
In certain applications, the equipment will automatically restart
and the LED will reset once the temperature has returned to
a safe operating level.
OIL
PRESSURE
SWITCH
OIL FILTER
HIGH TEMPERATURE
SWITCH
PAD
(SWITCH IS
OPTIONAL)
Figure 8-1. Engine Protective Devices
CHeCkING THe eNGINe oIl level
The oil capacity of the GTH/GTV-760/990 OHVI engine is
approximately 2 quarts. Refer to the chart on Page 14-1 for
the proper amount for each model. To check the engine oil
level, proceed as follows:
1. Remove the dipstick and wipe it dry with a
clean cloth.
2. Install the dipstick completely; then remove it again. The oil
level should be at the dipstick “Full” mark. If necessary, add
oil until the “Full” mark is reached. DO NOT FILL ABOVE
THE “FULL” MARK.
*
Never operate the engine with the oil level below
the “Add” mark on the dipstick. doing this could
damage the engine.
FILL / CHECK
Figure 8-2. Location of Oil Fill/Check (Vertical Shaft)
SeCTIoN 8: lubrICATIoN SYSTeM
8-1
8