Buell 2004 XB9S, Service Manual, Page: 54 / 597

2004 Buell Lightning: Maintenance 1-5
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FUEL AND OIL 1.2
FUEL
1
WARNING
1
WARNING
Remove filler cap slowly and fill fuel tank slowly to prevent
spillage; do not overfill or fill above the bottom of the filler
neck insert. In addition, leave air space to allow for fuel
expansion. Expansion can cause an overfilled tank to
overflow gasoline through the filler cap onto surrounding
areas. After refueling, be sure filler cap is securely tight-
ened. Failure to comply may cause an explosion or fire
which could result in death or serious injury.
Use a good quality unleaded gasoline (91 pump octane or
higher). Pump octane is the octane number usually shown on
the gas pump.
GASOLINE BLENDS
CAUTION
Using gasoline that has an alcohol additive, such as
methanol, may cause fuel system rubber components’
failure and/or engine damage.
Buell motorcycles were designed to give the best perfor-
mance using unleaded gasoline. Some fuel suppliers sell
gasoline/alcohol blends as a fuel. The type and amount of
alcohol added to the fuel is important.
● DO NOT USE GASOLINES CONTAINING METHANOL.
Using gasoline/methanol blends will result in starting and
driveability deterioration and damage to critical fuel sys-
tem components.
● ETHANOL is a mixture of 10% ethanol (Grain alcohol)
and 90% unleaded gasoline. Gasoline/ethanol blends
can be used in your motorcycle if the ethanol content
does not exceed 10%.
● REFORMULATED OR OXYGENATED GASOLINES
(RFG): “Reformulated gasoline” is a term used to
describe gasoline blends that are specifically designed to
burn cleaner than other types of gasoline. Your motorcy-
cle will run normally using this type of gas.
You may find that some gasoline blends adversely affect the
starting, driveability or fuel efficiency of your bike. If you expe-
rience one or more of these problems, we recommend you try
a different brand of gasoline or gasoline with a higher octane
rating.
ENGINE OIL
Use the proper grade of oil for the lowest temperature
expected before the next oil change.
If it is necessary to add oil and Harley-Davidson oil is not
available, use an oil certified for diesel engines. Acceptable
diesel engine oil designations include CF-4, CG-4, CH-4 and
CI4. The preferred viscosities for the diesel engine oils, in
descending order, are 20W-50, 15W-40 and 10W-40. At the
first opportunity, see a Harley-Davidson dealer to change
back to 100 percent Harley-Davidson oil.
See 1.6 ENGINE LUBRICATION SYSTEM for all service
information.
WINTER LUBRICATION
Combustion in an engine produces water vapor. During start-
ing and warm-up in cold weather, especially in freezing tem-
peratures, the vapor condenses to water before the
crankcase is hot enough to exhaust it through the breather
system. If the engine is run long enough for the crankcase to
become thoroughly heated, the water returns to vapor and is
then exhausted.
An engine used for only short trips, and seldom allowed to
thoroughly warm up, accumulates increasing amounts of
water in the oil pan. Water mixed with oil forms a sludge that
causes accelerated engine wear. In freezing temperatures,
the water becomes slush or ice, which may clog oil lines and
result in engine failure.
Always change the engine oil more often in winter. If the
engine is used for short runs, change the oil even more fre-
quently. The farther below freezing the temperature drops the
more often the oil should be changed.