Filed Under (Suzuki) by admin on 26-02-2011
FUEL PUMP The electric fuel pump is mounted at the bottom of the fuel tank, which consists of the armature, magnet, impeller, brush, check valve and relief valve . The ECM controls its ON/OFF operation as controlled under the FUEL PUMP CONTROL SYSTEM . When electrical energy is supplied to the fuel pump, the motor in the pump runs and together with the impel- ler . This causes a pressure difference to occur on both sides of the impeller as there are many grooves around it . Then the fuel is drawn through the inlet port, and with its pressure increased, it is discharged through the outlet port . The fuel pump has a check valve to keep some pressure in the fuel feed hose even when the fuel pump is stopped . Also, the relief valve is equipped in the fuel pump, which releases pressurized fuel to the fuel tank when the outlet of the fuel pressure has increased up to 450 -600 kPa (4.5- 6.0 kgf/cm2,64- 85 psi) . Relief valve Brush , ∎ I,’ Check valve Magnet L Armature When the impeller is driven by the motor, pressure differential occurs between the front part and the rear part of the blade groove as viewed in angular direction due to fluid friction . This process continuously takes place causing fuel pressure to be built up . The pressurized fuel is then let out from the pump chamber and discharged through the motor section and the check valve . FUEL SYSTEM AND THROTTLE BODY 5- 3 Inlet port I I Impeller 5-4 FUEL SYSTEM AND THROTTLE BODY FUEL PRESSURE REGULATOR The fuel pressure regulator consists of the spring and valve . It keeps absolute fuel pressure of 300 kPa (3.0 kgf/cm2,43 psi) to be applied to the injector at all times . When the fuel pressure rises more than 300 kPa (3 .0 kgf/cm2, 43 psi), the fuel pushes the valve in the regulator open and excess fuel returns to the fuel tank . 90 Spring 02 Valve FUEL INJECTOR The fuel injector consists of the solenoid coil, plunger, needle valve and filter . It is an electromagnetic type injection nozzle which injects fuel in the throttle body according to the signal from the ECM. When the solenoid coil of the injector is energized by the ECM, it becomes an electromagnet and attracts the plunger. At the same time, the needle valve incorporated with the plunger opens and the injector which is under the fuel pressure injects fuel in conic dispersion . As the lift stroke of the needle valve of the injector is set constant, the volume of the fuel injected at one time is determined by the length of time during which the solenoid coil is energized (injection time)
Filed Under (Mikuni) by admin on 31-10-2010
This manual is intended as a guide for users of Mikuni carburetors who want to learn the adjusting method to the best performance from our products. In motorcycles, special tuning of the engine is now considereda routine practice. The arrows that appear in the drawings in this text show the direction in which air, fuel and an air-fuel mixture flows, respectively. ¢JAir Fuel “Mixture Mounting angle fore and aft inclination of the carb should not exceed approx Function of a carburetor The function of a carburetor is to produce combustible air-fuel mixture, by breaking fuel into tiny particles (in the form of vapor) and by mixing the fuel with air in a proper ratio, and to deliver the mixture to the engine. A proper ratio (mixture ratio or air-fuel ratio) means an ideal air-fuel mixture that can burn without leaving an excess of fuel or air, Whether the proper mixture ratio is maintained or not holds the key to the efficient engine operation, 2. Air-fuel mixture required by the engine (Fig. 1) The ratio of a mixture of fuel and air is called the mixture ratio or the air-fuel ratio and is generally expressed by the weight proportion. Theoretically, the amount of air required for complete combustion of 1 gram of fuel under normal conditions is
Filed Under (Tips and Review) by admin on 25-10-2010
fuel injection (FI) systems have been around since the 1950′s and became widely used in cars during the 80′s. By the 1990′s all cars sold in the United States were equipped with FI systems, and though motorcycle manufacturers have included FI systems with some models as early as 1982, it isn’t until recently that the industry has seen wide spread use of FI. Since a lot of people come into my shop with questions about FI, I thought I would point out some of the differences between FI and carbureted systems as well as the benefits and disadvantages of both. A carbureted system is a mechanical system using air pressure to control the flow of fuel through the system. There are three basic parts in a carburetor, the throttle valve, the venturi and the float bowl. The throttle valve controls the amount of air that flows into the throat of the carburetor also known as the venturi which is simply a tapered hole through the carburetor body. As the venturi narrows, air moving through it is forced to speed up creating low pressure inside the carburetor. In a siphoning effect as the air tries to equalize the pressure, fuel is drawn in from the float bowl mixing with the air before entering the engine. The wider open the throttle valve, the more air will flow, drawing more fuel. A number of circuits are built into the carburetor in order to control the amount of air/fuel being drawn into the engine. In this context a circuit refers to a fuel passageway as opposed to an electrical circuit. In fact, nothing electrical controls fuel delivery in a carbureted system, it is all based on fluid flow, vacuum and hydraulics. The different circuits represent various throttle positions such as idle, partially open and fully open, and each of these circuits can be tuned to modify the efficiency of fuel delivery to the system. Fuel injection (FI) systems, on the other hand, rely on an electronic fuel pump to deliver fuel. The fuel pump delivers fuel at around 50psi as opposed to carbureted systems at normal atmospheric pressure of about 15psi. When the fuel reaches the injectors, the higher pressure allows much finer atomization (creating mist) of the fuel. The injectors then spray the atomized fuel into the intake manifold in a uniform conical pattern. The uniform pattern and fine atomization of the fuel spray increase the efficiency in which it is burned
Filed Under (Harley Davidson) by admin on 30-03-2012
1. Remove seat. 1 WARNING 1 WARNING To prevent spray of fuel, purge system of high-pressure fuel before supply line is disconnected. Gasoline is extremely flammable and highly explosive, which could result in death or serious injury. (00275a) 2. Purge the fuel supply line of high pressure gasoline. a. See Figure 4-36. Disconnect the fuel pump fuse from the main wiring harness. b. Start the engine and allow the vehicle to run. c. When the engine stalls, operate the starter for 3 seconds to remove any remaining fuel from the fuel lines. 1 WARNING 1 WARNING To prevent accidental vehicle start-up, which could cause death or serious injury, disconnect negative (-) battery cable before proceeding. (00048a) 3. Disconnect negative battery cable. 4. Remove instrument console. a. All but FXSTD, see Figure 4-37. Remove acorn nut and washer on instrument console to separate console from fuel tank. b. For FXSTD, see 8.26 INSTRUMENT CONSOLE: FXSTD. 5. Disconnect console wiring. Figure 4-36. Fuel Pump Fuse: View From Top Figure 4-37. Acorn Nut And Washer: All But FXSTD s0660x8xx 7526
4-28 2007 Softail: Fuel System HOME 1 WARNING 1 WARNING Gasoline can drain from the crossover line when disconnected from fuel tank. Gasoline is extremely flammable and highly explosive, which could result in death or serious injury. Wipe up spilled fuel immediately and dispose of rags in a suitable manner. (00259a) 6. Drain fuel tank. a. Obtain a short section of hose (5/16 inch I.D.). Insert bolt in one end of hose and install hose clamp to ensure that end is securely plugged. b. See Figure 4-38. Cut clamp (1) from one end of crossover hose (2). Quickly replace crossover hose on fuel tank fitting with open end of short hose while directing flow of gasoline from free end of crossover hose into suitable container. 7. See Figure 4-39. Unplug fuel pump module connector (3) . 8. Remove top plate screws (2) and discard. 9. See Figure 4-40. Pull top plate (2) out of fuel tank enough to expose fuel hose and clamp (1). CAUTION Carefully inspect end of hose for cuts, tears, holes or other damage. Replace hose if any damage is found. Even the smallest hole can cause a reduction in fuel pressure. 10. Cut clamp and remove hose from regulator housing fit- ting.
Filed Under (Harley Davidson) by admin on 28-02-2011
INSTALLATION To prevent accidental vehicle start-up, which could cause death or serious injury, remove main fuse before proceeding. (00251b) 1. Refer to the Service Manual and follow the instructions given to remove the main fuse. When servicing the fuel system, do not smoke or allow open flame or sparks in the vicinity. Gasoline is extremely flammable and highly explosive, which could result in death or serious injury. (00330a) 2. Remove the currently installed fuel tank from the vehicle. Follow the instructions for the correct model vehicle under FUEL TANK: EFI, REMOVAL in the Service Manual. 3. See FUEL PUMP/FUEL GAUGE SENDING UNIT, REMOVAL in the Service Manual for instructions to: a. Unplug the fuel pump module connector. b. Remove and discard the top plate screws. c. Remove the top plate, fuel pump and fuel level sender (fuel gauge sending unit) from the tank. NOTE Take care to avoid bending the fuel level sender float rod. A bent float rod will lead to erroneous gauge readings. 2 6 1 3 4 7 9 8 5 is05284 1. Fuel level sender 2. Electrical grounding tab 3. Fuel level sender lock tab 4. Adapter bracket 5. Slot (2) 6. Terminal strip insert 7. Sender to adapter lock tab 8. Slider 9. Adapter to tank lock tab Figure 1. Fuel Level Sender Assembly to Adapter – 4. See Figure 1. Clean the electrical grounding tab (2) on the back of the fuel level sender if necessary. The tab must make firm contact with the terminal strip insert (6) in the adapter bracket. Slide the original equipment (O.E.) fuel level sender (1) into the slots (5) in the new adapter bracket (4) as shown until the lock tabs (3 and 7) snap into place. Make sure the wire is not pinched between the adapter and sender. 5. See FUEL SUPPLY CHECK VALVE/TUBE in the Service Manual. Remove the check valve/quick-connect fitting assembly from the old fuel tank, and assemble to the new tank, using a new O-ring (purchased separately). 6. Fit the slider (8) on the adapter bracket into the fuel level sender mounting channel inside the tank, and push down until the lock tab (9) snaps into place. Make sure the sender and adapter wires are not pinched between the adapter and the fuel tank tunnel, and remain accessible through the fuel tank top opening. 7. See Figure 2. Obtain the assembly of the top plate (1), regulator (2) and fuel filter (3) removed from the old fuel tank, and the stainless steel screw (8) and nut (9) provided in this kit.