Fuel System Precautions
The EFI fuel system consists of the following components.
WARNING: Whenever working on the fuel system if a fuel hose is removed from any component, slowly bleed the pressure from the hose into an absorbent towel before removing the hose from the component.
- Gas tank
- Electric high output fuel pump
- Two pick-up valves with micron screens
- High-pressure fuel hose
- Fuel rail
- Fuel pressure regulator
- Throttle body assembly
- Injectors
- Fuel return hose
CAUTION: Always use resistor-type spark plugs and spark plug caps. Non-resistor components will cause the ECU to malfunction.
These above components are grouped into the fuel handling system. They work together along with five electrical sensors and the ECU to provide the engine with a precise fuel mixture for combustion. The five sensors are the following:
- Ignition Timing Sensor
- Intake Air Temperature Sensor
- Water Temperature Sensor
- Throttle Position Sensor
- Barometric Pressure Sensor
To start an engine for the first time or after performing service work on the fuel system, follow these steps:
- Place the emergency stop switch and the ignition switch in the ON position.
- Disconnect the yellow water temperature sensor lead wire at the ECU.
- Crank the engine over 6-8 times with the recoil starter.
- Reconnect the yellow sensor lead.
The fuel is first drawn into the electric fuel pump through two pick-up valves and hoses. The fuel is then routed through a high-pressure fuel hose to the fuel rail.
Start the engine without compressing the throttle. Repeat this procedure until the engine starts and builds RPM on its own.
If the engine becomes flooded, follow these steps:
- Set the brake lever lock.
- Compress the throttle lever to the full-open position.
- Crank the engine over until it starts and clears itself.
- Release the brake lever lock.
The fuel pressure is maintained at 37.9 +/- 2.2 psi (600 cc) and 48 +/- 2.2 psi in the fuel rail by the fuel regulator. If pressure exceeds this amount, the regulator opens and returns excess fuel to the gas tank through the fuel return hose.
NOTE: The entire EFI system depends on all coils functioning properly on the stator.
