Gravely 985103 User Manual
Page 30
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8.2 FUEL PUMP
The impulse style fuel pump is the most commonly
used fuel pump. Impulse fuel pumps may either be
mounted externally onto the carburetor fuel inlet or
remotely mounted. These pumps are connected in the
fuel line between the fuel supply and the carburetor or
directly to the fuel inlet.
Impulse fuel pumps are operated by crankcase
impulses created by the up and down movement of the
piston. A hose called a pulse line connects the fuel
pump diaphragm chamber and transmits the impulses
to the pump diaphragm. The impulses actuate the
diaphragm and the flap valves to lift the fuel from the
fuel tank to the carburetor.
8.3 FUEL SYSTEM CONTAMINATION
Any time fuel contamination is found in the fuel system
(dirt, water algae, etc.) replace the fuel, fuel filter and
flush the fuel lines. Remove the carburetor bowl and
clean. Replace all items that cannot be cleaned.
Reassemble the fuel system and check for proper
operation.
8.4 FUEL TANK
The fuel tank is made of composite material for long life
without breaking down from the additives used in
today’s blended fuels.