Fuel Line; Reducing The Fuel Pressure; Measuring The Fuel Pressure; Checking The Pressure Regulator - Yamaha F150A Service Manual

Fuel line

Reducing the fuel pressure

Before servicing the high-pressure fuel
line or vapor separator, make sure to
reduce the fuel pressure in the fuel line.
Otherwise, pressurized fuel could spray
out.
1. Remove the cap "1".
2. Cover the pressure check valve "a" of the
fuel rail using a rag, and then push the
pressure check valve "a" inward using a
flathead screwdriver to release the fuel
pressure.
3. Install the cap.

Measuring the fuel pressure

1. Reduce the fuel pressure. See "Reducing
the fuel pressure" (6-5).
2. Remove the cap "1".
3. Connect the special service tool "2" to
the pressure check valve "a".
To prevent fuel from leaking out, screw in
the gauge gently until it is connected
firmly.
Fuel pressure gauge "2":
90890-06753
4. Turn the engine start switch to ON, and
then measure the fuel pressure within 3
seconds.
TIP:
The fuel pressure will decrease 3 seconds
after the engine start switch is turned to ON.
1
Fuel pressure (reference data):
300.0 kPa (3.00 kgf/cm
5. Start the engine and warm it up until the
a
engine
650–750 r/min.
Fuel pressure (reference data):
260.0 kPa (2.60 kgf/cm
at engine idle speed
6. Turn the engine start switch to OFF.
7. Disconnect the special service tool, and
then install the cap.
Before disconnecting the special service
tools, cover the end of the hose using a
clean and dry rag.

Checking the pressure regulator

1. Reduce the fuel pressure. See "Reducing
the fuel pressure" (6-5).
2. Connect the special service tool. See
steps 2 and 3 in "Measuring the fuel
pressure" (6-5).
6-5
1
2
a
2
idle speed
2
Fuel line
2
, 43.5 psi)
stabilizes at
, 37.7 psi)