Kymco XCITING 500 - Service Manual > Schematic Drawing

FUEL SYSTEM

The fuel pump is operated by an electromagnetic force and its electrical energy is supplied from the battery. The fuel sent under pressure by the fuel pump flows into the float chamber when the float of the carburetor has dropped and the needle valve is open. When the needle valve closes, the pressure of the fuel in the hose connecting the carburetor and the fuel pump increases, and when the set pressure is reached, the operation of the fuel pump is stopped by the fuel pressure to prevent excessive supply.

FUEL PUMP CONSTRUCTION

When voltage is applied between the fuel pump terminals, current flows into the solenoid coil which then pulls up the plunger together with the diaphragm allowing fuel to be drawn into the pump. At this time, the contact which is linked with the plunger opens and interrupts current causing the coil to be de-energized. This allows the diaphragm to go down by the spring force, thereby pressurizing and delivering fuel to the outlet. When the fuel pressure builds up and overcomes the spring force, the plunger stops at pulled up position with the contact in open position.

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• When working with gasoline, keep away from sparks and flames.
• Note the locations of O-rings when disassembling and replace them with new ones during assembly.
• Before float chamber disassembly, drain the residual gasoline from the float chamber.
• Do not try to disassemble the automatic choke.
• When assembling the vacuum chamber and air cut-off valve, be careful not to damage the diaphragms.
• All cables, fuel lines and wires must be routed and secured at correct locations.
• When removing the fuel tank, keep sparks and flames away from the working area.
• When removing the fuel tank, the remaining fuel in the tank must be lower than 1/2 of the fuel tank capacity to avoid gasoline overflowing.
• Fuel tank capacity: 12.8 liters

SPECIFICATIONS

TROUBLESHOOTING

Engine does not start

• No fuel in tank
• Restricted fuel line
• Too much fuel getting to cylinder
• Clogged air cleaner
• Contaminated fuel
• Faulty fuel pump

Engine idles roughly, stalls or runs poorly

• Incorrect idle speed
• Rich mixture
• Lean mixture
• Clogged air cleaner
• Intake air leak
• Contaminated fuel
• Faulty air-cut off valve
• Damaged vacuum tube and connectors
• Damaged carburetor insulator

Throttle does not open fully, so engine stalls

• Damaged vacuum piston diaphragm
• Clogged diaphragm hole

Rich mixture

• Automatic valve opens excessively
• Faulty float valve
• Float level too high
• Clogged air jets
• Automatic choke valve set plate installed in the wrong groove
• Clogged air cleaner

Engine is hard to start

• No fuel in tank
• Restricted fuel line
• Clogged fuel strainer
• Faulty fuel pump
• Broken or clogged vacuum tube
• Faulty or clogged charcoal canister

Lean mixture

• Clogged charcoal canister
• Bent, kinked or restricted fuel line
• Clogged fuel strainer
• Float level too low

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