Caring for high voltage wires

In order to suppress BB radio interference, the wires laid between the spark plugs and the ignition distributor cover, as well as between the central terminal of the distributor cover and the ignition coil, are equipped with a carbon core instead of a copper conductive wire. Such a core breaks easily, so you should not unnecessarily bend the wires and, when disconnecting from the spark plugs, pull exclusively on the tip, and in no case on the wire itself. Care must also be taken when connecting wires. Breaking the core of the BB wire can cause misfiring in the engine.

Check all HV wires for external insulation defects (scuffs and cracks), replace if necessary. In no case should you attempt to repair a damaged wire. Before checking, the wires should be cleaned by wiping with a rag soaked in kerosene, then dried thoroughly.

Measurement of resistive resistance of explosive wires

Note. If an ohmmeter is available, the resistive resistance of the HV wires can be measured.

1. Having removed the distributor cover together with the BB wires connected to it, start measuring the resistance of each of the wires one by one by connecting the ohmmeter probes to the spark plug wire tip and the corresponding terminal inside the distributor cover (see accompanying illustration). The resistance must not exceed 30 kOhm.


2. If the measurement result exceeds 30 kOhm, disconnect the corresponding wire from the distributor cap and repeat the measurement for the wire separately. If the result is confirmed, the wire must be replaced.

3. Increased resistance in the distributor cap may be due to oxidation of its terminals. In this case, traces of corrosion must be removed from the terminals using a suitable small scraper or sandpaper.

Note. Also inspect the distributor cap inside and out for cracks and carbon tracks between the BB terminals. If such defects are found, the cover should be replaced.

Also check the condition of the carbon brush in the central part of the distributor cap. replace if there is evidence of arcing or other damage.