Page 1
17. IGNITION SYSTEM
17-0
17
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IGNITION SYSTEM
__________________________________________________________________________________
IGNITION SYSTEM LAYOUT --------------------------------------- 17-1
SERVICE INFORMATION -------------------------------------------- 17-2
TROUBLESHOOTING ------------------------------------------------- 17-2
SPARK PLUG ----------------------------------------------------------- 17-3
IGNITION COIL INSPECTION --------------------------------------- 17-3
A.C. GENERATOR INSPECTION ------------------------------------ 17-4
CDI UNIT INSPECTION----------------------------------------------- 17-4
17
Page 2
17. IGNITION SYSTEM
17-1
IGNITION SYSTEM LAYOUT
IGNITION CIRCUIT
Ignition Coil
Pulser Coil
Ignition Switch
Spark Plug
CDI Unit
A.C. Generator
A.C. Generator
R
B/Y
Ignition Switch
Pulser Coil
Spark Plug
G
Br/LYL/Y
G
Reg
Rec
W
G
Page 3
17. IGNITION SYSTEM
17-2
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• Check the ignition system according to the sequence specified in the Troubleshooting. (1-28)
• The ignition system adopts CDI unit and the ignition timing cannot be adjusted.
• If the timing is incorrect, inspect the CDI unit and A.C. generator and replace any faulty parts.
Inspect the CDI unit with a CDI tester
• Loose connector and poor wire connection are the main causes of faulty ignition system. Check
each connector before operation.
• Use of spark plug with improper heat range is the main cause of poor engine performance.
• The inspections in this section are focused on maximum voltage. The inspection of ignition coil
resistance is also described in this section.
• Inspect the ignition switch according to the continuity table specified in page 20-3.
• Inspect the spark plug referring to Section 3.
• Remove the A.C. generator and pulser coil referring to Section 10.
SPECIFICATIONS
Item
Standard
SH10BA
BR8HSA
Spark plug
SH10AA
BR6HSA
Spark plug gap
0.8_ 1.0mm
Ignition timing
13.5°± 2° BTC/200
0rpm
Primary coil
0.153_ 0.187Ω
Ignition coil resistance
(20℃ )
Secondary
without plug cap
3.24_ 3.96KΩ
coil
with plug cap
6.99_ 10.21KΩ
Pulser coil resistance (20℃ )
50_ 170Ω
Exciter coil resistance (20℃ )
50_ 350Ω
Ignition coil primary side max. voltage
244V
Pulser coil max. voltage
10.5V
Exciter coil max. voltage
244V
TESTING INSTRUMENT
Electric tester
TROUBLESHOOTING
No spark at plug Engine starts but turns poorly
• Faulty spark plug • Ignition primary circuit
• Poorly connected, broken or shorted wire —Faulty ignition coil
• Faulty ignition switch —Poorly connected wire or connector
• Faulty ignition coil —Poorly contacted ignition switch
• Faulty CDI unit • Ignition secondary circuit
• Faulty A.C. generator —Faulty ignition coil
—Faulty spark plug
—Faulty high-tension wire
—Poorly insulated plug cap
• Improper ignition timing
—Faulty A.C. generator
—Stator not installed properly
—Faulty CDI unit
Page 4
17. IGNITION SYSTEM
17-3
SPARK PLUG
For spark plug inspection and adjustment,
refer to page (3-5).
IGNITION COIL INSPECTION
Remove the seat and met-in box. (2-3)
Remove the ignition coil
IGNITION COIL PERFORMANCE TEST
Test the ignition coil using a CDI tester.
When there is no spark at the spark plug,
replace the ignition coil with a new one.
IGNITION COIL CONTINUITY TEST
Inspect the continuity of the ignition coil,
primary coil and secondary coil.
Measure the ignition coil resistances at
20℃ .
Primary coil
0.153_ 0.187Ω
Secondary coil
without plug cap
3.24_ 3.96KΩ
Secondary coil with
plug cap
6.99_ 10.21KΩ
Ignition Coil
Correctly operate the CDI tester following
the manufacturer‘s instructions.
＊
This is a general test. Accurate ignition
coil test must be performed with a CDI
tester.
＊
Ignition Coil
Ignition Coil
Secondary Coil
Primary Coil
Ignition Coil
Spark Plug
CDI Tester
Special Coupler (KB7)
CDI Unit
Page 5
17. IGNITION SYSTEM
17-4
A.C. GENERATOR INSPECTION
For A.C. generator removal/installation, refer
to pages 9-3 and 9-5.
Disconnect the pulser coil wire coupler.
Measure the pulser coil resistance between
the blue/yellow wire and ground.
Resistance (20℃ ): 80_ 160Ω
For pulser coil replacement, refer to pages 9-3
and 9-5.
CDI UNIT INSPECTION
Remove the met-in box. (2-3)
Disconnect the CDI coupler and remove the
CDI unit.
Inspect the CDI unit performance using the
CDI tester.
Connect the CDI unit to the CDI tester
special coupler (KB7). Adjust the CDI tester
switch range.
Switch
Good CDI
Faulty CDI
1. OFF
2. P
3. EXT
4. ON1
5. ON2
No spark
↑
↑
Good spark
Good spark
Good spark
No spark
No spark
A.C. Generator Connector
Pulser Coil Wire Coupler
CDI Tester
CDI Tester Special Coupler
CDI Unit
Correctly operate the CDI tester following
the manufacturer‘s instructions.
＊
Measure the resistance in the XΩ range.
＊
Page 6
17. IGNITION SYSTEM
17-5
RESISTANCE INSPECTION
Measure the resistance between the terminals.
Replace the CDI unit if the readings are not
within the specifications in the table below.
Use the x KΩ range for the Sanwa Tester.
Use the x 100Ω range for the Kowa Tester.
Unit: KΩ
Probe⊕
(-)Probe
Blue /
Yellow
Brown/
Blue
Green
Black/
Yellow
Blue /
Yellow
∞
1~100
∞
Brown/
Blue
100~1~100
∞
Green
1
~
∞
∞
∞
Black/
Yellow
1~100
∞
0.1~50
• Due to the semiconductor in circuit, it
is necessary to use a specified tester
for accurate testing. Use of an
improper tester in an improper range
may give false readings.
• Use a Sanwa Electric Tester (07308-
0020000) or Kowa Electric Tester
(TH-5H).
• In this table, “Needle swings then
returns” indicates that there is a
charging current applied to a condenser.
The needle will then remain at “∞ ”
unless the condenser is discharged.
＊
Br/L
L/Y
B/Y
G
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