Buell 2005 FIREBOLT, Service Manual, Page: 368 / 621

2005 Buell Firebolt: Fuel System 4-99
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IGNITION COIL 4.32
TROUBLESHOOTING
Follow the troubleshooting procedures listed under 4.8 INI-
TIAL DIAGNOSTIC CHECK if the engine will not start, is diffi-
cult to start or runs roughly. Also check condition of spark
plug cables. Insulation on cables may be cracked or damaged
allowing high tension current to short to metal parts. This
problem is most noticeable when cables are wet.
If poor starting/running condition persists, check resistance of
ignition coil primary and secondary windings using an ohm-
meter.
Ignition Coil Primary Circuit Test
1. Remove ignition coil. See REMOVAL which follows.
2. Set ohmmeter scale to RX1.
3. See Figure 4-70. Place multimeter wires on primary coil
windings (1).
4. Check for primary coil winding resistance.
a. Normal resistance range is 0.5-0.7 ohms.
b. See TEST RESULTS if resistance is not within nor-
mal operating range.
Ignition Coil Secondary Circuit Test
1. Remove ignition coil. See REMOVAL which follows.
2. Set ohmmeter scale to RX1K.
3. See Figure 4-70. Place multimeter wires on secondary
coil windings (2).
4. Check for secondary coil winding resistance.
a. Normal resistance range is 5.5-7.5K ohms.
b. See TEST RESULTS if resistance is not within nor-
mal operating range.
Test Results
1. A low resistance value indicates a short in the coil wind-
ing. Replace coil.
2. A high resistance value might indicate that there is some
corrosion/oxidation of the coil terminals. Clean the termi-
nals and repeat resistance test. If resistance is still high
after cleaning terminals, replace coil.
3. An infinite ohms (
∞
or no continuity) resistance value
indicates an open circuit (a break in the coil winding).
Replace coil.
Ignition Coil Substitution
If a coil tester is not available, use the following test.
NOTE
Coil will function without being attached to frame.
1. Substitute a new ignition coil by attaching it to any con-
venient point near the old coil. Transfer terminal wires to
new coil.
2. Attach new spark plug cables to coil and plugs.
3. Test system. If ignition trouble is eliminated by the tem-
porary installation of a
new coil, carefully inspect old coil
and cables for damage. The insulation on the cables may
be cracked or otherwise damaged allowing high tension
current to short to metal parts. This is most noticeable in
wet weather or after the motorcycle has been washed.
Figure 4-70. Ignition Coil Testing
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b0675x7x
2
1 1
Terminal B
+12 V
Terminal C
(front coil)
Terminal A
(rear coil)
1. Primary Resistance should be 0.5-0.7 ohms.
2. Secondary Resistance should be 5.5-7.5K ohms.
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b0993x4x
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