Spark Plugs - Buell 2002 X1 Handbook

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SPARK PLUGS

INSPECTION
Check spark plugs:
Inspect at every 5000 mile (8000 km) service interval.
G
Replace every 10,000 mile (16,000 km) service interval.
G
Use only Harley-Davidson 10R12 spark plugs (Part No.
G
27661-00Y).
1. Remove left side air scoop to access front cylinder spark
plug. See 2.36 AIR SCOOP.
2. Disconnect cables from both spark plugs.
3. Remove spark plugs.
4. See Figure 1-40. Compare your observations of the plug
deposits with the descriptions provided below.
a. A wet, black and shiny deposit on plug base, elec-
trodes and ceramic insulator tip indicates an oil
fouled plug. The condition may be caused by one or
more of the following: worn pistons, worn piston
rings, worn valves, worn valve guides, worn valve
seals, a weak battery or a faulty ignition system.
b. A dry, fluffy or sooty black deposit indicates an air-
fuel mixture that is too rich and/or engine idling for
excessive periods.
c. A light brown, glassy deposit indicates an over-
heated plug. This condition may be accompanied by
cracks in the insulator or by erosion of the elec-
trodes and is caused by an air-fuel mixture that is
too lean, a hot-running engine, valves not seating or
improper ignition timing. The glassy deposit on the
spark plug is a conductor when hot and may cause
high-speed misfiring. A plug with eroded electrodes,
heavy deposits or a cracked insulator must be
replaced.
d. A plug with a white, yellow, tan or rusty brown pow-
dery deposit indicates balanced combustion. Clean
off spark plug deposits at regular intervals.
5. If the plugs require cleaning between tune-ups and
replacement plugs are not available, proceed as follows:
a. Degrease firing end of spark plug using ELECTRI-
CAL CONTACT CLEANER. Dry plug with com-
pressed air.
b. Use a thin file to flatten spark plug electrodes. A
spark plug with sharp edges on its electrodes
requires 25-40% less firing voltage than one with
rounded edges.
6. If the plugs cannot be cleaned, replace with No. 10R12
spark plugs.
7. Check electrode gap with a wire-type feeler gauge. Gap
should be 0.038-0.043 in. (0.97-1.09 mm).
1-34
4636
Figure 1-40. Typical Spark Plug Deposits
7037
11-18 ft-lbs
(15-24 Nm)
Loctite Anti-Seize
Figure 1-41. Spark Plugs (Typical)
8. See Figure 1-41. Apply LOCTITE ANTI-SEIZE to plugs.
Install and tighten to 11-18 ft-lbs (15-24 Nm).
9. Connect spark plug cables. Longer cable attaches to
rear cylinder spark plug. Verify that cables are securely
connected to coil and spark plugs.
10. Install left side air scoop. See
1.18
2.36 AIR SCOOP.
2002 Buell X1: Maintenance