Fuel Systems & Governors

1. Fuel Systems & Governors

2. Student Objectives: • Students will be able to identify the different types of fuel systems. • Students will be able to identify fuel system services. • Students will be able to identify different parts of fuel systems. • Students will demonstrate how to troubleshoot fuel systems. • Students will be able to identify what a governor is and how it works.

3. Fuel Systems & Basic Components: • Pressurized fuel system- used when the fuel tank is located a considerable distance below the carburetor. • Vapor locked- when the temperature of the air around or inside a carburetor becomes high enough to vaporize the gasoline, pockets of vapor will stop all flow of fuel. • Fuel stabilizer- keeps fresh fuel fresh and promotes quick, easy starts after the engine has been stored for an extended time.

4. Fuel Systems & Basic Components (cont.) • Fuel pump- a mechanical or electrical device that draws gasoline from the fuel tank and delivers it to the carburetor or injector pump. • Carburetor- a device for automatically mixing fuel in proper proportion with air to produced a combustible gas. • Governor- a mechanical, hydraulic, or electrical device that controls and regulates speed.

5. Fuel System, Parts, and Assembly

6. Vapor Return Fuel System

7. How a pressurized fuel system works: • The carburetor is connected to the fuel tank through the fuel filter by fuel lines. • Fuel flow from the tank to the carburetor is induced by pressure transmitted from the crankcase to the air space above the fuel line level via the air line, which runs from the pressurized valve to the twist connector and into the top of the fuel tank. • For starting, initial flow to the carburetor is induced by the hand-operated priming pump.

8. How a pressurized fuel system works (cont.) • A disc filter is incorporated in the bottom of the fuel pick-up tube. • The fuel level is indicated by a graduated sector, actuated by a float attached to an arm. • The pressure release valve in the center of the carrying handle permits relieving pressure when necessary. • The check valve in the twist connector permits disconnecting the air-fuel line without loss of tank pressure.

9. How a pressurized fuel system works (cont.) • The tank pressure forces fuel up through the pick-up line, through the filter, and into the carburetor. • The check valve is essential to the operation of the priming pump.

10. Governor System

11. Governor System • The speed governing system consists of a proportional regulator, a speed relay, and a servomotor controlling the gate opening.

12. Outside of Carburetor that is connected to the fuel system.

13. Inside of a carburetor

14. Troubleshooting Carburetors

15. Troubleshooting Carburetors (cont.)

16. Troubleshooting Carburetors (cont.)

17. Troubleshooting Carburetors (cont.)

18. Troubleshooting Carburetors (cont.)

19. Fuel Pump

20. Fuel Pump/Sending Unit

21. Fuel Stabilizers • Fuel stabilizers- prevent fuel deterioration and protects engines from gum, varnish, rust, and corrosion. • Liquefied Petroleum Gas- (LPG) may be propane, butane, or a mixture of both.

22. Advantages of LPG • Cheaper, especially when close to the source (refinery). • Less oil consumption due to engine wear. • Reduced maintenance costs- longer engine life between overhauls. • Smoother power from the slow, even burning of LPG. • Fewer noxious or poisonous exhaust gases, such as deadly carbon monoxide gas.

23. Disadvantages of LPG • Initial equipment costs are high. Bulk fuel storage and carburetion equipment are costly. • Fewer accessible fuel points (gas stations). • Harder to start LPG engines in cold weather.

24. Sources • Roth, Alfred C. Small Gas Engines. Tinley Park, Illinois: Goodheart-Willcox Company, Inc. • www.Keveny.com • http://images.google.com