TOHATSU BFT 250A, Service Manual

Page: 232 / 639

5-110
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FUEL SYSTEM
FUEL PRESSURE MEASUREMENT
Relieve the fuel pressure (page 5-66).
Remove the service check bolt and set the special tool
in the threaded bolt hole.
Disconnect the pressure regulator vacuum tube [1] from
the intake manifold [2] and clamp the vacuum tube.
Remove the propeller:
– Standard rotation type (page 16-6)
– Counter rotation type (page 17-5)
Set the outboard motor gear case in a test tank filled
with water. Start the engine and measure the fuel
pressure at idle.
When the fuel pressure is outside the specified
standard pressure, check the following:
• When fuel pressure is higher than standard
pressure:
– Check fuel hose A, joint hose, and fuel pipe for
clogging.
– Check the high pressure side fuel pump for proper
operation (page 5-113).
• When fuel pressure is lower than standard pressure:
– Check the pressure regulator for proper operation
(page 5-111)
– Check the high pressure side fuel pump for proper
operation (page 5-113).
– Check fuel hose A, joint hose, and fuel pipe for
leaking.
– Check the high pressure side fuel filter for an
obstruction (page 5-106).
After measuring fuel pressure, install the service check
bolt (page 5-66).
Gasoline is highly flammable and explosive.
You can be burned or seriously injured when
handling fuel.
• Keep heat, sparks, and flame away.
• Wipe up spills immediately.
• Handle fuel only outdoors.
TOOL:
Fuel pressure gauge,
0 – 100 psi [1] 07406-004000B
[1]
Standard fuel pressure
[At idle speed of 650 ± 50 min -1
(rpm)]:
280 – 330 kPa (2.9 – 3.4 kgf/cm
2
, 41 – 48 psi)
[1]
VAPOR SEPARATOR
VACUUM TANK
[1]
PRESSURE
REGULATOR
FUEL
INJECTOR
[2]
[2]