Buell 2002 P3, Service Manual

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2002 Buell P3: Electrical 7-23
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IGNITION COIL 7.9
GENERAL
See Figure 7-24. The ignition coil is mounted on the frame
underneath the fuel tank on left side above airbox.
See Figure 7-18. The ignition coil is a pulse-type transformer.
Internally, the coil consists of primary and secondary wind-
ings with a laminated iron core. The contents are sealed in a
waterproof insulating compound. The ignition coil is not
repairable. Replace the unit if it fails.
The low-voltage ignition primary circuit consists of the coil pri-
mary winding, ignition module and battery. When the circuit is
closed, current flows through the coil primary winding creat-
ing a strong magnetic field in the iron core of the ignition coil.
When the ignition module receives a signal from the cam
position sensor and trigger rotor, the ignition module inter-
rupts (opens) the ignition primary circuit, which causes the
magnetic field in the coil core to collapse.
The collapsing magnetic field induces a high-voltage electri-
cal discharge in the ignition secondary circuit, which consists
of the coil secondary winding, spark plug cable and spark
plug. The high-voltage discharge produces a spark to bridge
the electrode gap of the spark plug.
The ignition coil fires the spark plug at the end of the com-
pression stroke (no-waste spark).
TROUBLESHOOTING
Follow the troubleshooting procedures listed under 7.8 IGNI-
TION MODULE/ CAM POSITION SENSOR if the engine will
not start, is difficult to start or runs roughly. Also check condi-
tion of the spark plug cable. Insulation on cable may be
cracked or damaged allowing high tension current to short to
metal parts. This problem is most noticeable when cable is
wet.
If poor starting/running condition persists, check resistance of
ignition coil primary and secondary winding using an ohmme-
ter.
Ignition Coil Primary Circuit Test
1. Remove ignition coil.
2. Set ohmmeter scale to RX1.
3. See Figure 7-25. Using harness connector adaptor kit
(HD-41404) gray female probes and patch cord, place
multimeter wires on primary coil windings. See Page 7-7.
4. Check for primary coil winding resistance.
a. Normal resistance range is 0.4-0.6 ohms.
b. See TEST RESULTS on the next page if resistance
is not within normal operating range.
Ignition Coil Secondary Circuit Test
1. Remove ignition coil.
2. Set ohmmeter scale to RX1K.
3. See Figure 7-26. Using harness connector adaptor kit
(HD-41404) gray female probes and patch cord, place
multimeter wires on secondary coil windings. See Page
7-7.
4. Check for secondary coil winding resistance.
a. Normal resistance range is 7,720-9,440 ohms.
b. See TEST RESULTS on the next page if resistance
is not within normal operating range.
Figure 7-24. Ignition Coil (Left Side)
Figure 7-25. Ignition Coil Primary Resistance Test
7796
Spark Plug Post
Connector [83]
Mounting Screws (2)
7797
B A