Generac Power Systems 941-2 Service Manual page 101

TESTING FOR SPARK:
To test the ignition system, a suitable spark tester
may be used. Such spark testers are commercially
available. Test the system as follows:
Warning! Do NOT use a screwdriver to test for
!
spark. Personal injury or damage to equip-
ment may result.
1. Disconnect the high tension lead from the spark plug.
2. Attach the spark plug high tension lead to the spark tester ter-
minal.
3. Connect the spark tester clamp to the engine cylinder head.
4. Crank the engine rapidly. Engine must be turning at 350 rpm or
more. If spark jumps the tester gap, you may assume the igni-
tion system is operating satisfactorily.
If sparking across the tester gap does NOT occur, go
to "CHECK POWER SUPPLY."
Figure 8. Testing for Spark
CHECKING ENGINE MISS:
To determine if an engine miss is ignition related,
connect the spark tester in series with the spark
plug's high tension lead and the spark plug. Then,
start the engine. If spark jumps the tester gap at regu-
lar intervals but the engine miss continues, the prob-
lem is in the spark plug or in the fuel system.
Figure 9. Checking Engine Miss
ENGINE IGNITION SYSTEM
CHECK POWER SUPPLY:
When the engine is being cranked, battery voltage
should be available from the A6060 circuit board to a
4-terminal connector via Wire 14. From the 4-terminal
connector, battery voltage should be available to the
Ignition Module via Wire 14 (RED wire). And battery
voltage should be available from the Ignition Module
to the Ignition Sensor via a RED wire. If this 12 VDC
power supply is not available, the ignition system will
not function. To check the power supply, proceed as
follows using a volt-ohm-milliammeter (VOM):
1. Gain access to the control panel interior.
2. In the panel, locate the 3-pin connector that interconnects the
Ignition Module and the Ignition Sensor.
3. Press down on the connector lock tang and disconnect the two
connector halves.
NOTE: A single large black lead carries the three
leads from the Ignition Sensor to the 3 pin MALE
connector. The three leads from the Ignition
Module (brown, green and red) attach to the 3 pin
FEMALE connector.
4. Set the VOM to a scale that will allow battery voltage to be
read (about 12 volts DC).
5. Connect the meter test leads across the center FEMALE pin
(RED wire) and frame ground.
6. Hold the Start-Run-Stop switch at "START". The meter should
read battery voltage.
Figure 10.
If battery voltage is NOT indicated, go to Step 7. If
battery voltage IS indicated, go to "CHECK IGNITION
SENSOR."
7. Now locate the 4-terminal connector in the panel.
Connect the VOM test leads across the terminal and
frame ground. Crank the engine and the VOM should
read battery voltage.
a. If battery voltage is indicated now but was NOT
indicated in Step 6, test Wire 14 (RED) between
the 4-terminal connector and the Ignition Module.
If wire is bad, repair or replace as necessary.
Section 6.4
(continued)
Page 6.4-3