1. Fuel Systems 2

2. Objectives  Understand Fuel Lines and tanks  Understand Fuel Pumps and filters

3. Fuel Tanks  Used to store fuel  Made of plastic or steel  Newer engines made of plastic  Fuel Caps  Vented to prevent a vacuum in the tank  Vacuums prevent engine operation  Caps also have a set of thin plates called baffles to prevent dust and particles from entering the tank

4. Fuel Tanks  Fuel Strainer  Located in the tank to prevent contaminates during fueling  Fuel Fittings  Connects fuel lines to system parts  Outlet Filter Screen  Screens particles as fuel leaves the tank  Shut off Valve  Closes fuel tank outlet  Fuel Lines  Made of metal, synthetic rubber or flexible nylon

5. Fuel Filters  Unclean fuel can clog the carburetor preventing operation  Water in the fuel line can cause detonation  Fuel filter are used to remove any impurities of fuel  Most newer filters are disposable and have paper filament to catch impurities

6. Fuel Pumps  Most fuel systems use a gravity fed system to pull the fuel to the carburetor  Fuel Pump  A pump that creates a low pressure to move fuel to the carburetor

7. Mechanical Fuel Pump  Pumps using a lobe on the camshaft to pump the fuel out  The lobe moves a rocker arm up and down that serves as a pump  Like a plunger

8. Impulse Fuel Pump  Utilizes Pressure impulses in the intake manifold  Intake manifold  Part that delivers the air-fuel mixture form the carburetor to the intake port

9. Primer  A bulb used to force fuel into the air entering the combustion chamber  Used to start a cold engine  Has not ran for several hours