Oil Pump - Buell 2002 X1 Handbook

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OIL PUMP

GENERAL
See Figure 3-53. The oil pump consists of two gerotor gear
sets, feed and scavenge (return), housed in one pump body.
The feed set distributes oil to the engine, the scavenge set
returns oil to the tank.
A gerotor-type gear set has two parts — an inner and an
outer gerotor. The inner gerotor has one less tooth than the
outer gerotor. Both gerotors have fixed centers which are off-
set to each other.
In a gerotor gear set, oil is transferred from inlet to outlet as it
is trapped between the rotating inner and outer gerotors. The
illustration below shows the principle of gerotor operation:
1. During the first 180° of rotation, the cavity between inner
and outer gerotors gradually increases in size until it
reaches its maximum size, equivalent to the full volume
of the "missing tooth." The gradually enlarging cavity cre-
ates a vacuum into which oil flows from the inlet.
2. During the next 180° of rotation, the size of the cavity
decreases forcing oil into the outlet.
b0098x3x
Inner Gerotor Outer Gerotor
1
Oil Inlet Oil Outlet
Oil trapped between inner
and outer gerotor teeth
2002 Buell X1: Engine
See
pump through the feed hose connector (5). It is forced by the
gerotor feed set (7) through a hose to the oil filter. Return oil
from the flywheel compartment is drawn back into the pump
and is forced by the gerotor scavenge set (9) back to the oil
tank.
See
the engine.
The oil pump seldom needs servicing. Before you disassem-
ble an oil pump suspected of not producing adequate oil
pressure, be absolutely certain that all possible related mal-
functions have been eliminated:
1.
2.
3.
Oil drawn into cavity
between gerotor teeth
2
3
Figure 3-53. Principle of Gerotor Operation
Figure 3-55. Gravity-fed oil from the oil tank enters the
INTERNAL ENGINE PASSAGES
Make sure all oil hose clamps are tight and that hoses
are not pinched or damaged.
Check oil level and condition of oil in tank. Pressure will
be affected if oil is diluted. In freezing weather, proper
circulation of oil can be affected if the oil feed hose
becomes clogged with ice and sludge.
Check for a grounded oil pressure switch wire or faulty
switch if oil indicator light fails to go out with engine run-
ning.
Oil Inlet
Oil Outlet
Oil trapped between
gerotor teeth
3.13
for oil passages within
Oil forced out
Oil
Outlet
4
3-37