Suzuki DF 40 Service Manual page 67

IGNITION TIMING CHART
The following chart is an example for ignition at BTDC30°.
CKP Sensor Signal 1
CKP Sensor Signal 2
CKP Sensor Signal 3
CMP Sensor Signal
ON
#1 Ignition Signal
OFF
#3 Ignition Signal
#2 Ignition Signal
Cm.
CONTROL MODE
WHEN CRANKING :
The ignition timing is fixed at BTDC 7° until the engine starts.
WHEN IDLING / TROLLING :
The ignition timing is controlled to within the range of BTDC 5° to 13° to provide stable engine operation at
the specified idling / trolling speed.
When the shift lever is in neutral, if engine speed exceeds 1200 r / min , ignition timing remains fixed at
BTDC 9°.
WHEN RUNNING (NORMAL OPERATION) :
The ignition timing ranges between BTDC 0° – 32° (DF40) or 25° (DF50), depending on current engine
operating conditions.
WHEN DECELERATING :
When the throttle valve is closed suddenly, turning the CTP switch "ON", ignition timing is delayed for a
programmed duration to prevent engine stalling or unstable running.
SPECIFICATION
Ignition system
Advance
Ignition timing
Firing order
BTDC 65° on #1 exhaust stroke
120° 120° 120° 60°
30°
30°
In. Cm. Ep. Ex.
TDC
Ex. In. Cm. Ep.
TDC TDC
Ep. Ex. In.
TDC
TDC
In.: Intake, Cm.: Compression,
DF 40 : BTDC 0° – 32°,
ENGINE CONTROL SYSTEM
Spark timing
In. Cm. Ep.
TDC TDC
Ex. In. Cm.
TDC
Cm. Ep. Ex. In.
TDC TDC
Ep.: Explosion
Full-transistorized ignition
Electronic microcomputer control
1 – 3 – 2
Ex. In. Cm. Ep.
TDC TDC
Ep. Ex. In.
TDC TDC
Cm. Ep. Ex.
TDC
Ex.: Exhaust
DF 50 : BTDC 0° – 25°
3-12
Ex.
Cm. E
TDC
In.
TDC