Suzuki DF 60 Service Manual

ENGINE CONTROL SYSTEM 3-19
Duty cycle signal for fuel pump
(example: 70% duty)
“ON” time
1 cycle time
× 100 = duty (%)
OFF
ON
0.7 ms
1 ms (1 cycle)
Time
Battery
charge
coil
Rectifier &
regulator
30A fuse
Battery
ECM
CPU
Sensor/switch
signal input
FP
ECM
main
relay
Ignition
switch
15A
fuse
Fuel
pump
FUEL PUMP CONTROL SYSTEM
OUTLINE
To supply the optimum fuel amount, the ECM controls the fuel pump drive duty cycle, a repeated ON / OFF
signal, at a specified rate (1000 times a second).
Based on engine speed and battery voltage, the ECM determines the optimum duty (repeating “ON” time
rate within a cycle) and sends this signal to the fuel pump.
CONTROL MODE
BEFORE START:
For 3 seconds after ignition switch is turned “ON”, the pump is controlled to operate at 100% duty in order to
initially pressurize the high pressure line.
WHEN CRANKING:
The pump is controlled to operate at 100% duty.
WHEN RUNNING (NORMAL OPERATION):
The pump is controlled to operate at 60 – 100% duty based on the current engine speed and battery voltage.
CKP sensor:
Informs ECM of engine speed.
Battery voltage:
Ignition switch:
Informs ECM of “START” signal.
ECM
Fuel pump
Signal
FP

Suzuki DF 60 Specifications

General

Cylinders	3
Steering	Remote
Starting System	Electric
Max Power Output	60 hp
Trim Method	Power Trim and Tilt
Engine Type	4-stroke
Displacement	941 cc
Fuel Delivery System	Sequential Multi Point Fuel Injection
Maximum Output	60 HP
Full Throttle Operating Range	5, 300 - 6, 300 rpm
Recommended Fuel	Unleaded gasoline
Exhaust	Through propeller hub
Cooling System	Water-cooled
Warranty	3-year limited warranty