Ignition System

IGNITION SYSTEM

3 Main switch
7 Fuse "IGNITION" (10A)
8 "ENGINE STOP" switch
9 Pickup coil
10 T.C.I, unit
11 Ignition coil (#2, #3)
12 Ignition coil (#1, #4)
13 Sidestand relay
48 Battery
49 Fuse "MAIN" (30A) 

DESCRIPTION

This model is equipped with a battery operated, fully transistorized, breakerless ignition system. By using magnetic pickup coils, the need for contact breaker points is eliminated. This adds to the dependability of the system by eliminating frequent cleaning and adjustment of points and ignition timing. The TCI (Transistor Control Ignition) unit incorporates an automatic advance circuit controlled by signals generated by the pickup coil. This adds to the dependability of the system by eliminating the mechanical advancer. This TCI system consists of two units; a pickup unit and an ignitor unit.

OPERATION

The TCI functions on the same principle as a conventional DC ignition system with the exception of using magnetic pickup coils and a transistor control box (TCI) in place of contact breaker points.

Pickup Unit

The pickup unit consists of two pickup coils and a flywheel mounted onto the crankshaft. When the projection on the flywheel passes a pickup coil, a signal is generated and transmitted to the ignitor unit. The width of the projection on the flywheel determines the ignition advance.

1  Pickup coils

Ignitor Unit

This unit controls wave form, duty control, switching, electronic ignition advance, etc. The duty control circuit reduces electrical consumption by controlling the duration of the primary ignition current.

The ignitor unit 1 also has a protective circuit for the ignition coil. If the ignition switch is on and the crankshaft is not turning, the protective circuit interrupts the current flow to the primary coil after a few seconds. When the crankshaft is turning, however, the ignitor unit sends current to the primary coil.

1. Remove:
• Seat
• Left side cover
• Panel
• Ignitor unit 1

TROUBLESHOOTING

1. Start engine and warm-up a while, then turn it off.

2. Connect Electro Tester (90890-03021) 1
2  Spark plug wire  
3  Spark plug

3.  Start engine and increase spark gap until misfire occurs (Test at various rpm between idle and red line.)

CAUTION:
Do not run the engine in neutral above 6,000 rpm for more than 1 or 2 seconds.

Minimum Spark Gap: 6 mm (0.24 in)

4. If ignition system becomes inoperative or engine misfires see the troubleshooting chart below:

Troubleshooting Chart

Check ignition coil resistance (primary and secondary).

IGNITION COIL

1. Remove the fuel tank

2. Disconnect the ignition coil leads 1

2 No. 2 and No. 3 cylinder ignition coil

3. Measure the primary coil resistance 

Primary Coil Resistance: 
O  to R/W  lead connector 
Gy  to R/W  lead connector 
2.7Ω ± 10% at 20°C (68°F)

4. Measure secondary coil resistance 

Secondary Coil Resistance: 
12kΩ ±20% at 20°C (68°F)

5. Connect:

 Electro tester 1
 Fully charged battery 2 (to ignition oil leads)
3 No. 1 (Rear) cylinder high tension cord 
4 Ground 
5 R/W lead 
6 O lead

6. Measure the ignition coil minimum spark gap Turn the spark gap adjuster and increase the gap to the maximum limit unless misfire occurs first. 

Minimum Spark Gap: 6 mm (0.24 in)

PICKUP COIL

1.  Remove:
• Left side cover
• Panel

2.  Disconnect pickup coil wires from TCI unit wires.

3. Measure the pickup coil resistance. Use pocket tester.

Pickup Coil Resistance:

No. 1 and No. 4 cylinder (O — B)
No, 2 and No. 3 cylinder (Gy - B)

120Ω ± 10% at 20°C (68°F)

SIDESTAND RELAY

1. Remove:

• Left side cover
 •Sidestand relay 1

2. Check the relay contacts

Use 12V battery 3 and Pocket Tester (90890-03112).

Battery Connected: ∞ 2 
Battery Disconnected: 0Ω  1

SPARK PLUG

1. Check condition and replace if burned or fouled. Clean and regap as necessary.

CAUTION:
Be sure to use plugs of proper type

D8EA (NGK) X24ES-U (NIPPONDENSO)

Electrode Gap 1 :

0.6 ~ 0.7 mm (0.024 - 0.028 in)

2. Install spark plug

Spark Plug: 17.5 Nm (1.75m*kg, 12.5ft-lb)

1 Finger tighten

2 Plug wrench tighten