Hercules — Electronic Ignition Primary Voltmeter Test
Testing & diagnosis · Electronic ignition system
From a Hercules service manual — check it applies to your exact model before use.
Before you start
- Check the secondary section before troubleshooting the electronic section.
Procedure
- Position trigger wheel so sensor is between two teeth.
- Turn ignition switch on; check battery voltage, should be 12 to 13 volts.
- Check coil positive terminal voltage, within one volt of battery.
- Check coil negative terminal voltage; should be 4 to 8 volts.
- Place screwdriver on sensor face; voltage should rise to 12 to 13 volts.
- If no change, replace electronics; adjust sensor gap to .008 inch.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Battery voltage 12-13 V
- Coil positive within 1 V of battery
- Coil negative 4-8 V
- Sensor air gap .008 in.
Source: Hercules service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.