buell s1 lightning '97 Manual
1-27
SPARK PLUGS
INSPECTION
Check spark plugs:
●
Inspect at every 5000 mile (8000 km) service interval.
●
Replace every 10,000 mile (16,000 km) service interval.
1.
Disconnect cables from both spark plugs.
2.
Remove spark plugs.
3.
See
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.
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 a carbu-
retor air-fuel mixture that is too rich, engine idling for
excessive periods of time and/or enrichener usage
for excessive periods of time.
retor air-fuel mixture that is too rich, engine idling for
excessive periods of time and/or enrichener usage
for excessive periods of time.
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.
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.
off spark plug deposits at regular intervals.
4.
If the plugs require cleaning between tune-ups, proceed
as follows:
as follows:
a. Degrease firing end of spark plug using ELECTRI-
CAL CONTACT CLEANER. Dry plug with com-
pressed air.
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.
requires 25%-40% less firing voltage than one with
rounded edges.
5.
If the plugs cannot be cleaned, replace with No. 6R12
spark plugs.
spark plugs.
6.
Check electrode gap with a wire-type feeler gauge. Gap
should be 0.038-0.045 in. (0.96-1.14 mm).
should be 0.038-0.045 in. (0.96-1.14 mm).
7.
See
Apply LOCTITE ANTI-SEIZE to plugs.
Install and tighten spark plugs to 11-18 ft-lbs (15-24 Nm).
8.
Connect spark plug cables. Verify that cables are
securely connected to coil and spark plugs.
securely connected to coil and spark plugs.
Figure 1-37. Typical Spark Plug Deposits
Figure 1-38. Spark Plugs
4636
5581
Tighten to 11-18
ft-lbs (15-24 Nm)
ft-lbs (15-24 Nm)