1. The contact closed angle is the angle in degrees that the breaker cam rotates during the time between the moment the contacts close and the moment they open. The breaker contacts are adjusted so that the angle of their closed state meets the manufacturer's requirements. If the gap between the contacts is too large, the angle will be too small, if the gap is too small, it will be large.
2. The closed angle of the contacts is measured using a special device, connected in accordance with the manufacturer's instructions. Pay special attention to how to use the gauge on 4-cylinder engines, as many instruments can be designed for use with 4-, 6-, and 8-cylinder engines. Check that the instrument can be used for negative negative ignition systems "earth".
3. Angle measurement is made as follows. If necessary, set the device to zero. This is only possible if the device has an adjusting screw on the needle pivot. Connect the red wire of the device to the wire connecting the coil to the ignition switch, and the black wire to "earth". Disconnect the low voltage wire connecting the coil to the distributor. Ask an assistant to turn on the starter for a few seconds and check the meter readings. Using the adjusting screw, ensure that the needle of the device takes the position required by the instructions, after which the device is ready for operation.
4. After preparing the device for operation, disconnect the black wire from "land" and connect it to the low voltage wire between the coil and the distributor, which was disconnected to bring the device to zero. Again, ask the assistant to turn on the starter and check the instrument readings. Compare the obtained value with the one indicated in Specifications.
5. If an incorrect value is obtained, it is necessary to adjust the gap between the contacts of the breaker, as indicated in the previous section. Remember that to reduce the angle you need to increase the gap (and vice versa).
6. After adjusting the gap between the contacts, check the angle of their closed state again. When the correct value is obtained, disconnect the device and connect the low voltage wire between the coil and the distributor.