Generac Power Systems GN190H, Руководство по обслуживанию и ремонту

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SECTION 8: IGNITION SYSTEM
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GENER
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GENERAL
The ignition system typically used on GN-190, GN-191 and
GN-220 engines is a solid-state (breakerless) type. The system
utilizes a magnet on the engine flywheel to induce a relatively
low voltage into an ignition coil assembly. Ignition coil inter-
nal components increase the voltage and deliver the resulting
high voltage across the spark plug gap.
The ignition coil houses a solid state-circuit board that con-
trols ignition timing. Timing is fixed, nonadjustable and spark
advance is automatic.
MAJOR COMPONENTS
Major components of the ignition system include (a) the
ignition coil assembly, (b) the spark plug, (c) the engine run
switch and (d) the engine flywheel (see Figures 8.1 and 8.4).
Figure 8.1 — Ignition System Components
IGNITION COIL ASSEMBLY
Solid-state components encapsulated in the ignition coil are
not accessible and cannot be serviced. If the coil is defective,
the entire assembly must be replaced. The air gap between
the coil and the flywheel magnet is fixed and nonadjustable.
The ignition coil assembly (Figure 8.2) consists of (a) igni-
tion coil, (b) spark plug high tension lead and (c) spark
plug boot.
Figure 8.2 — Ignition Coil Assembly
SPARK PLUG
The spark plug should be cleaned and regapped periodi-
cally. The plug should be replaced every 100 hours of operation
or once annually, whichever comes first.
Recommended spark plug is a Champion RC12YC or equiva-
lent. Set spark plug gap to 0.030 inch (0.76mm) (Figure 8.3).
NOTE: Always use original GENERAC® replacement
parts.
Figure 8.3 — Setting Spark Plug Gap
FLYWHEEL
CHECKING FLYWHEEL MAGNET:
The flywheel magnet rarely loses its magnetism. If you sus-
pect a magnet might be defective, a rough test can be
performed as follows:
1. Place the flywheel on a wooden surface.
2. Hold a screwdriver at the extreme end of its handle and
with its point down.
3. Move the tip of the screwdriver to about 3/4 inch (19mm)
from the magnet. The screwdriver blade should be pulled
in against the magnet.
FLYWHEEL KEY:
In all cases, the flywheel’s taper is locked on the crankshaft
taper by the torque of the flywheel nut. A keyway is provided
for alignment only and theoretically carries no load.
If the flywheel key becomes sheared or even partially
sheared, ignition timing can change. Incorrect timing can result
in hard starting or failure to start.
FLYWHEEL REMOVAL:
Use a strap wrench to prevent the flywheel from turning.
Remove the FLYWHEEL NUT. Then, remove the CONICAL
WASHER and the STARTER CUP.
SET PLUG GAP AT 0.030 inch
(0.76 mm)
SPARK
PLUG
ENGINE
RUN SWITCH
IGNITION
COIL
ASSEMBLY