First, classification and structure of gasoline pumps

Efi motorcycles set environmental protection, fuel saving, good start and other advantages in one, deeply loved by the people. Nowadays, EFI motorcycles have gradually replaced the motorcycles in the carburetor era, and the fuel pump of the EFI system serves as an important part of the fuel supply system, which provides the high-pressure fuel required by the EFI system.

The fuel pump structure can be divided into two types according to the location of the installation: one is the external type, the fuel pump assembly is set outside the tank, such as the 2008 SUZUKI Suzuki Falcon fuel pump, this old fuel pump due to its poor heat dissipation conditions, large volume, heavy weight has been eliminated from use, belongs to the past tense. Instead, it is currently used quite widely reliable, lightweight fuel pump, that is, built-in fuel pump. The fuel pump is placed in the gasoline tank of the motorcycle, and the gasoline liquid in the tank is used to cool the heat of the fuel pump, so that the fuel pump can work for a long time to ensure the normal operation of the engine. At present, both pedal, straddle and domestic and imported motorcycles use built-in fuel pumps.

Second, the structure and working principle of gasoline pump

Motorcycle electric fuel pump is mainly composed of pump body, permanent magnet motor and shell three parts. After the permanent magnet motor is energized, it drives the impeller in the pump body to rotate, the fuel is sucked from the oil inlet, through the fuel pump inside, and then pressed out from the oil outlet to supply the fuel system with pressure.

When the fuel flows through the fuel pump, it also has a cooling effect on the armature of the permanent magnet motor, because the fuel pump motor is soaked in the fuel tank fuel, there is no air, and it is impossible to catch fire when the fuel pump is working. The motor of the fuel pump has a permanent magnet fixed to the housing, which is used to generate an electromagnetic force. The base of the gasoline pump assembly consists of a fuel pump power supply, a fuel sensor connector harness, a connector socket and a fuel output interface.

Three, the failure of the gasoline pump

The fuel pump of the motorcycle EFI system will produce the following faults in daily use:

1. Due to the long use time of the motorcycle, the quality of the gasoline filled in the use of the gasoline does not meet the requirements, or the frequent use of the gasoline filled with the low grade, resulting in the primary and secondary fuel filter blocking of the gasoline pump, and the decrease of the fuel flow resulting in insufficient fuel in and out, so that the fuel output pressure is reduced.

2, the failure of the fuel pump of the fuel system, the fuel pump motor is damaged (the fuel level of the fuel tank is too low to work for a long time, the fuel must be filled in time, otherwise it is easy to burn the fuel pump), and the fuel pump impeller is seriously worn, causing the output fuel pressure of the fuel pump to drop.

3. In the process of disassembling the gasoline pump during maintenance, the sealing ring of the oil pump and the sealing ring of the oil drain valve are not assembled in place, or the O-ring is damaged by assembly, resulting in a drop in the fuel pressure of the gasoline pump.

4, the fuel supply system circuit caused by the failure, the power is not in place (fuse blown, oil pump lead plug is not in place or open, plug-in poor contact) or fuel relay failure.

5, the fuel pump assembly in the pressure relief valve failure, caused by excess pressure relief.

6, due to the age of the motorcycle, or long-term storage, the fuel tank corrosion, the fuel tank internal treatment process is not good, causing the inner wall of the fuel tank corrosion, corrosion and blockage of the oil filter, gasoline supply is not on, resulting in insufficient fuel pressure of the fuel pump.

7. The oil pump output pipe of the gasoline pump assembly in the fuel tank and the oil pipe output interface are broken (such as the old golden wing, some Harley, and some Ducati models), and the oil leakage causes the fuel pressure to drop, resulting in the engine being difficult to start, the engine working abnormally or even unable to start.

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