Misfire; General - Buell 2008 XB SERIES Electrical Diagnostics Manual

MISFIRE

GENERAL

Misfire at Idle or Under Load
Misfire conditions may be caused by:
Battery condition and connections.
Fuel system problems. See tables under
DIAGNOSTIC CHECK.
DIAGNOSTICS
PART NUMBER
HD-26792 SPARK TESTER
HD-41404-B HARNESS CONNECTOR TEST KIT
Diagnostic Notes
Each reference number below correlates to a circled number
on the flow chart(s).
Wipe up spilled fuel and dispose of rags in a suitable
manner. An open spark around gasoline could cause a
fire or explosion, resulting in death or serious injury.
(00518b)
1. See Figure 2-43. A SPARK TESTER (Part No. HD-26792)
must be used to verify adequate secondary voltage
(25,000 volts) at the spark plug.
a. Turn ignition switch OFF.
b. Remove spark plug cable from spark plug. Visually
check plug condition.
c. Attach cable to spark tester. Clip tester to cylinder
head bolt.
d. While cranking engine, watch for spark to jump tester
gap on leads.
e. Reinstall and repeat procedure on other spark to jump
tester gap on leads.
2. Perform spark plug cable resistance test.
a. Remove spark plug cable from spark plug and ignition
coil.
b. Using an ohmmeter, touch probes to terminals on
each end of plug wire.
c. Compare resistance values to
cables not meeting specifications. Reinstall and repeat
procedure on other spark plug cable.
2-50 2008 Buell XB Diagnostics: Engine Management
2.8 INITIAL
TOOL NAME
Table 2-25. Replace
3. If carbon tracking is evident, replace ignition coil and
inspect spark plug wires. Wires must be clean and tight.
Excessive wire resistance or faulty connections can cause
ignition coil damage. See
(24), P2303 (25), P2304
4. This test can also be performed by substituting a known
good ignition coil for one causing the no spark condition.
The ignition coil does not require full installation to be
functional. Verify faulty ignition coil by performing resist-
ance test. See 2.37 DTC P2300 (24), P2301 (24), P2303
(25), P2304 (25).
5. Use HARNESS CONNECTOR TEST KIT (Part No. HD-
41404-B), gray pin probe and patch cord.
ed01468
Figure 2-43. Spark Tester
Table 2-25. Spark Plug Cables
SPECIFICATION
Length
Resistance
2.16
2.37 DTC P2300 (24), P2301
(25).
FRONT & REAR
5.75 in. (146 mm)
1,430-3,360 ohms