Generac Power Systems GTH1000, Service Manual

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5. Check the (-) negative side of the system. Place the VOM (+)
positive lead on the starter case and the other lead on the (-)
negative post of the battery. Crank the engine and observe the
reading, it should be less than .2 volts.
6. If greater than 0.2 volts, check all wire connections on the (-)
negative side of the starter. There should not be any readings
higher than 0.2 volts.
STARTER AMP DRAW TEST
This test requires a special tool called a clamp-on type amp meter.
Most repair shops should be able to perform this test.
1. Place the amp meter clamp on the (+) positive cable running
from the battery (+) post to the starter post.
2. Ground the ignition and crank the engine (no longer than 15
seconds). The starter amp draw should be less than 100 amps
during cranking.
Excessive draw could be caused by the following:
• Faulty starter. To verify this, the starter should be removed from
the engine and bench checked prior to replacing. Do an amp draw
test on the bench. The starter should not exceed 62 amps with a
minimum pinion speed of 3250 rpm. See Figure 6-5.
• Engine oil viscosity too heavy (see engine manufacturer’s Opera-
tors Manual).
STARTER
CONTACTOR
STARTER
MOTOR
TACHOMETER
12 VOLT
BATTERY
CLAMP ON
AMP METER
VISE
Figure 6-5. Testing Starter Motor Performance
• Some equipment manufacturers may use a constant drive pump,
which may have too heavy of oil or too tight of belt tension.
• Internal engine problem. Turn the engine over with a socket and
ratchet to make sure it turns over easily.
• Battery cable is loose or too small.
• Battery terminals are corroded.
• Battery CCA too low.
BATTERY INFORMATION
A 12 volt battery is required to operate the starter motor on Generac
OHVI V-Twin engines. For best starter life and performance, the bat-
tery should have a rating of at least 450 cold cranking amps at 0°F for
gasoline engines and 525 cold cranking amps for LP engines.
*
WARNING: Wear eye protection when servicing the battery.
Avoid skin contact. If contact does occur, flush with cold water
and consult a physician.
*
CAUTION: Before servicing battery, disconnect negative (-)
battery cable and then disconnect the positive (+) battery
cable.
*
WARNING: Batteries produce hydrogen, an explosive gas. Do
not store or charge a battery near an open flame or devices
which utilize a pilot light or can create a spark.
Figure 6-6. Typical Battery
INSTALLATION:
1. Before installing battery, connect all equipment to be
operated.
SECTION 6: ELECTRIC STARTER
6-3
6