Fixing a motorcycle ignition problem can be a big headache. With so many parts involved in the ignition process, it can be difficult to nail down which one is causing the problem. Troubleshooting a motorcycle ignition problem is a matter of narrowing the possibilities.
When your motorcycle will not start, the first thing you should check is whether the battery has a charge or not. Check the battery with a voltmeter and verify that it reads 12 volts direct current (VDC). If it does, check that all the connections are secure and free of damage. Check that the water-acid mix in the battery is at the correct fill line in all of the cells. If the mixture is low in a cell, take the top off and fill the cell with deionised or distilled water. Do not put in tap water as the chemicals in your local water supply will damage the battery. Once you have filled the battery, charge it overnight.
Engine Won't Start
If your engine will not start, turn the key and see if the indicator light comes on. If it does not, there is a serious problem with the electrical system. At his point, the wiring or the ignition switch is probably at fault. Have a look at the wiring to see if it is in place and free of damage. Unplug everything that is electrical, clean these parts, then plug them back in. Test to see if the bike will start. Check next for faulty fuses, unplugging each one and replacing it with a known good fuse to see if the problem is resolved. Fuses are cheap and can be bought at a motorcycle repair garage. Check that the spark plug is clean and plugged in. Try a new spark plug to see if that helps.
If the bike does begin to start but cuts out, the problem may not be with the ignition system but with the fuel lines. Check that the bike does not have any leaks from the fuel area. Check the fuel lines for clogs or leaks, and check the fuel filter to see if it is clogged. Loosen the float bowl drain screw from the gas tank and allow a small amount of gas to flow out. Check for water or dirt to see if your fuel is tainted. If the motorcycle starts but stalls, it is likely a fuel and not an ignition problem. If the bike does not want to turn over at all, you likely have a more serious ignition problem that requires professional diagnosis.