Ignition ht coils

Primary winding resistance 2.6 to 3.2 ohms @ 20°C

Secondary winding resistance

with plug caps and leads 17.2 to 22.8 K-ohms @ 20°C

without plug caps and leads 13.5 to 16.5 K-ohms @ 20°C

5«2 Ignition system

General information

All models are fitted with a fully transistorised electronic Ignition system, which due to its lack of mechanical parts is totally maintenance free. The system comprises a rotor, pulse generator coil, ignition control unit and ignition HT coils (refer to the wiring diagrams at the end of Chapter 9 for details).

The ignition triggers, which are on the rotor mounted on the right-hand end of the crankshaft, magnetically operate the pulse generator coil as the crankshaft rotates. The pulse generator coil sends a signal to the ignition control unit which then supplies the ignition HT coils with the power necessary to produce a spark at the plugs.

The system uses two coils which are mounted on a bracket behind the steering head. The lower coil supplies no. 1 cylinder spark plug and the upper one supplies no. 2 cylinder spark plug.

The ignition control unit incorporates an electronic advance system controlled by signals generated by the ignition triggers and the pulse generator coil.

The ignition system incorporates a safety interlock circuit which will cut the ignition if the sidestand is put down whilst the engine is running and in gear, or if a gear is selected whilst the engine is running and the sidestand is down. It also prevents the engine from being started if the sidestand is down and the engine is in gear unless the clutch lever is pulled in.

Because of their nature, the individual ignition system components can be checked but not repaired. If ignition system troubles occur, and the faulty component can be isolated, the only cure for the problem is to renew the part. Keep in mind that most electrical parts, once purchased, cannot be

returned. To avoid unnecessary expense, make very sure the faulty component has been positively identified before buying a new part.

Note that there is no provision for adjusting the ignition timing on these models.

2 Ignition system - check %>

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A Warning: The energy levels in electronic systems can be very high. On no account should the ignition be switched on whilst the plugs or plug caps are being held. Shocks from the HT circuit can be most unpleasant. Secondly, it is vital that the engine is not turned over or run with any of the plug caps removed, and that the plugs are soundly earthed (grounded) when the system is checked for sparking. The ignition system components can be seriously damaged if the HT circuit becomes isolated.

1. As no means of adjustment is available, any failure of the system can be traced to failure of a system component or a simple wiring fault. Of the two possibilities, the latter is by far the most likely. In the event of failure, check the system in a logical fashion, as described below.

2. Disconnect the HT leads from the spark plugs. Connect each lead to a spare spark plug and lay each plug on the engine with the threads earthed (grounded) (see illustration). If necessary, hold each spark plug with an insulated tool.

A Warning: Do not remove any of the spark plugs from the engine to perform this check - atomised fuel being pumped out of the open spark plug hole could ignite, causing severe injury!