motor image by Klaus Eppele from Fotolia.com. The ignition coil on a motorcycle serves to step up the relatively low battery voltage to the high voltage needed to fire a spark plug. Coils are generally a sealed, water-tight component. As such, they are generally not a repairable item.Routine checks on a coil are not necessary.nstructions. Turn off the motorcycle ignition. Disconnect the spark plug wires from the coil by hand. Disconnect the two smaller primary wires from the coil using an open-ended wrench.