After the rev-limiting ignition coil was added to the karting Ducar 212 class rules, we received numerous calls from customers reporting that their engines were reaching 6,000 RPM, even though the coil should limit it to 5,200-5,300 RPM. After extensive testing and input from an experienced engine builder, we discovered that using Autolite Racing's AR3910X spark plug is causing the issue. The fix is to switch back to the Ducar OEM spark plug or use the Autolite Racing AR3910 spark plug. Dyno testing will show the performance differences between the AR3910X, OEM spark plug, and AR3910. Please note, using the AR3910X could result in post-race disqualification. If you have any questions, feel free to call us at 910-655-9035.
