Before connecting a tachometer to your vehicle, be sure that the tachometer being used is compatible with the ignition system. Installing incompatible equipment could cause damage to the system.
Before setting timing, make sure the headlights, heater fan, engine cooling fan and any other electrical equipment is turned off. If any current drawing systems are operating, vehicle's which are equipped with idle up systems, will operate the systems causing the idle speed to be higher than normal. An incorrect ignition timing will be set if the adjustment is made under these conditions.