Checking and testing of the ignition coil primary winding and secondary winding resistance. By the use of multi tester, test the resistance between positive and negative terminal of ignition coil. The test must have 1.3 to 1.6 ohms resistance. Test secondary winding resistance between positive terminal and center tower terminal. It must have 10.7 to 14.5 kilo ohms.
Check power source line using the voltmeter, check voltage at the positive terminal. Turn the ignition switch to on position, connect the positive probe of voltmeter to the negative side of terminal to engine body or ground. Approximately 12 volts power supply.
Check primary circuit by checking lose connection in the primary circuit. Battery, ignition switch, ignition coil, condenser, contact point. Grounded circuit can lead to malfunctioning of ignition system and produce spark. Check the open wire.
Check the contact point for corrosion and burns produced by the electric arcing when contact point close.
Check the distributor cap from corrosion, breaks and oil. Carbon contact at the cap center tower breaks that it cannot contact with the rotor.
Check the high tension cable from cracks, scratches, burns and open insulation. This can cause spark when it touches engine body. Test the high tension cable resistance, It must less than 25 kilo ohms.
Check spark plug by conducting spark test. Inspect spark plug gap. The gap ranges from 0.8 mm to 1.1 mm. Clean the spark plug tip. Inspect porcelain insulation for cracks.
Inspect rotor and distributor assembly. Check rotor tip from corrosion or bend. Check also distributor shaft for play. Condenser wire and contact point wire must not be grounded at distributor body.
