General Tips for Replacing a Motorcycle Ignition System

a red Motorcycle

A motorcycle ignition system is necessary for your motorcycle to start. The system is made up of several parts, each of which can have their own problems. You can usually replace the motorcycle ignition system yourself and this is much cheaper than having a mechanic do the work for you.

Parts of the Ignition System

The motorcycle ignition system is made up of separate parts:


Trigger coil

Ignition coil

Black box

When the magnet on the flywheel passes the trigger unit, it’s the trigger coil that commands the black box unit to send out a spark that causes ignition.


When you replace the motorcycle ignition system, you need to make sure the timing is properly adjusted. The belt has to be set to very specific points in order for the release of gasoline from the fuel system to coincide with the ignition spark.

You can find the specific timing measurements for your make and model in your owner’s manual. The adjustments aren’t easy for those who haven’t done them before so you might need the help of a friend or a professional in order to set the belt correctly.

Checking the Components

You might not need to replace the entire motorcycle ignition system. The problem, for example, could be in the ignition coil. It’s worthwhile checking the components before replacing everything.

You can check the ignition coil by removing the spark plug wires then taking off the other two connected wires with a wrench. Taken an ohmmeter and set it to Rx1 then hold the probes against the smaller connectors on the coil. Look for a reading of between 2.5 ohms and 3.1 ohms. If you get any other reading, the ignition coil is faulty.

You can confirm your readings by setting the ohmmeter to Rx1,000 ohms and holding the probes against the connections for the spark plug wires. Unless your reading is between 10,000 ohms and 12,500 ohms, your ignition coil is damaged. You should replace it but you shouldn't need to replace the entire motorcycle ignition system.

In many instances, simply replacing the ignition coil will take care of any ignition problems you might be experiencing without having to undertake any further work.


When you’re replacing the motorcycle ignition system, you should also check your battery to ensure it’s putting out enough power for the bike. If it’s too weak, there won’t be enough power running to the ignition system and this might even be the crux of the problem.

The real lesson to learn is that you don’t automatically have to replace the entire ignition system just because there’s a problem. Test each element and troubleshoot the problem before taking any course of action that might be expensive and time-consuming.

Spark Plugs

If you replace the motorcycle ignition system, you should also replace the spark plugs on the bike, especially if the old ones have been on for a while. When you remove the old ones, inspect them carefully. If one of them is quite white, it’s a sign that it might have been receiving a lean mixture. Alternatively, if one is very dark, it has been getting an overly rich mixture. You will need to adjust your carburetor to rectify this problem.