Operation Manual

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2
IGNITION SYSTEM
Spark Test
Test Magnetron armature on the engine. Before
replacing the armature, be sure that the problem
is not in the wiring or switches.
NOTE: Engines with Magnetron ignition will
show spark at the tester even if the flywheel key
is sheared.
Connect the spark plug wire (A) to the long
terminal of Ignition Tester #19368 ([B] Fig. 1).
Ground the tester to the engine with the alligator
clip.
Fig. 1
Operate starter and be sure the RPM is 350 or
more. Observe tester gap in window of tester.
If spark jumps tester gap:
• Ignition is good.
If spark does not jump tester gap:
• Check the ignition coil.
Spark Miss Test
1. To determine if an engine miss is ignition
related, use Ignition Tester #19368, in
series with spark plug lead and spark
plug.
2. Start and run engine.
If spark consistently jumps the tester gap but
the miss continues:
• The problem is downstream from the
tester.
1. Check the spark plug.
2. Check compression.
3. Check fuel system and/or carburetion.
If spark in tester gap is erratic:
• Check ignition coil and associated wiring.
CARBURETION
Before checking the carburetion, be sure the fuel
tank has an ample supply of fresh, clean
gasoline. Be sure that the shutoff valve (if
equipped) is open and fuel flows freely through
the fuel line. Make sure the choke closes
completely. If engine will not start, remove and
inspect the spark plug as follows:
Wet plug symptoms:
• Overchoking
• Excessively rich fuel mixture
• Water in fuel
• Float needle valve stuck open
• Plugged air cleaner
WARNING
Prevent accidental starting. Remove the
spark plug wire from the spark plug.
Ground the wire after removal. Failure to do
so can cause personal injury.
WARNING
Do not check for spark with spark plug
removed.