A custom ignition for your go-kart engine will enable you to fire up more quickly and get off the line well ahead of your race competitors. Follow these directions to build a customized ignition for your go-kart engine to improve its performance off the start line and throughout the race.
Step 1 - Determine the Ignition Timing of Your Current Engine
To customize your go-kart engine's ignition, you want it to have an advanced timing curve so it will fire the spark plugs faster. Check the spark plug timing with a specialized spark plug timer when the engine is running to determine your engine's current ignition timing.
Step 2 - Adjust the Ignition Pickup by Moving It Nearer the Flywheel
You can move the ignition pickup a few millimeters (1/10 inch) closer to the flywheel so it signals the spark plugs to fire at shorter intervals. Drill holes in the ignition pickup mount bracket to relocate the ignition pickup where you want it. Use the grinder to smooth the holes so they will hold the ignition pickup mounting bracket securely.
Step 3 - Adjust the Flywheel
Instead of relocating the ignition pickup, you can alter the flywheel itself to adjust the ignition timing. Remove the flywheel carefully from the engine and grind it with the electric grinder so one of its flanges is offset from its original position. This moves the flywheel itself closer to the ignition pickup, an easier process than detaching and resetting the ignition pickup.
Step 4 - The Easiest Change for a Custom Ignition
To the old ignition system, add a capacitance discharge ignition for improved performance. This type of ignition has advanced timing programmed into the ignition sequence. Ensure you install a CDI that can advance the timing, not just increase the RPM (revolutions per minute) of the engine. Or, you can buy a modification kit and replace the entire ignition system.
Step 5 - How to Install a Capacitance Discharge Ignition
You can purchase a CDI as part of a modification kit specifically designed for your go-kart's 150cc engine, or you can buy the ignition module alone. To change it, you can pop out the old ignition module and swap in the new one. If you are experienced with engine work, purchase the entire ignition modification kit. You will be replacing the ignition pickup, flywheel, spark plugs and applicable wiring. Follow the guides provided with the modification kit, or ask someone who has done similar modifications to their go-kart engine to lend you a hand.
Step 6 - Other Ways to Improve Ignition Effectiveness
Once you have installed your custom ignition, improve its function by putting in a high-capacity air filter and flow system that will increase the air intake. This will make your fuel mixture leaner enabling more performance out of a given amount of gas, and helping your spark plugs fire more cleanly. You can also modify the carburetor to draw more fuel at a more effective rate to boost ignition power and output.