Generac Power Systems 941-2 - Manual (Page 100)

Section 6.4
ENGINE IGNITION SYSTEM
IGNITION MODULE (CONTINUED)
Figure 4. Ignition Module
IGNITION COIL
Primary ignition voltage (12 VDC) is delivered from
the Ignition Module to the Ignition Coil. The Coil
boosts the voltage and delivers the high voltage to
the engine Spark Plug.
Figure 5. Ignition Coil
SPARK PLUG
The Spark Plug on the GV-220 engine is a Champion
RC12YC (or equivalent).
Figure 6. Setting Spark Plug Gap
Clean the Spark Plug and reset its gap to 0.030 inch
(0.76mm) every 100 hours of operation. Clean by
scraping or wire brushing and washing with commer-
cial solvent. DO NOT blast clean the spark plug.
SUMMARY OF OPERATION
See Figure 6. As the generator's permanent magnet
rotor turns, magnets in the Rotor hub's Ignition Cage
rotate past an Ignition Sensor at fixed intervals.
Battery voltage is delivered to an Ignition Module dur-
ing cranking and running, via Wire 14. From the
Ignition Module, battery voltage is also delivered to
the Ignition Sensor via the RED (+) lead. The Ignition
Sensor acts as a "trigger" mechanism, causing the
Ignition Module to deliver its output to the Ignition Coil
at timed intervals. Current flows through the primary
coil of the Ignition Coil and then collapses to induce a
high voltage into the Ignition Coil's secondary coil.
This high voltage (about 25,000 volts) is delivered to
the park Plug to fire the spark plug gap.
Components encapsulated in the Ignition Module pro-
vide an automatic spark advance. At cranking
speeds, ignition will occur at about 15'-18' BTDC. At
higher speeds, ignition can occur up to 29° BTDC.
Figure 7. Ignition System Diagram
IGNITION TIMING
Ignition timing is fixed and non-adjustable.
TESTING THE SYSTEM
GENERAL:
Solid state components inside the Ignition Sensor,
Ignition Module and Ignition Coil are not accessible and
cannot be serviced. If any of these components is
defective, the entire component must be replaced. The
system does not include an armature and there is no air
gap to adjust, or breaker points to adjust or replace.
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