Divide by 2 for "wasted spark" motorcycle rev counter input

My motorcycle just got an upgraded ignition timing method. This new method fires the spark plugs twice each cycle which in turn increases the RPM * 2 according to the tachometer.

Is there a way to half the amount of outputs the sensor is sending to the tachometer? Its been a while since I’ve done anything with electronics so I was looking into d flip flops to throw out every other output but I don’t know how hard this is to recreate on a 12-15v system or if there is a simpler solution for my problems.