Re: Champion Spark Plugs
ANY non-suppressor spark plug can "cause" RFI. The plugs don't actually cause the RFI, the ignition coil does. Almost all of the OMC-built cd-ignition systems require a "Q" style Champion plug, Q designates Suppressor-Resistor. The NGK plugs, although they are a resistor-type, don't offer the suppression feature the Evinrudes and Johnsons require. <br /><br />Here's my understanding: When the voltage (250v) that is stored in the charge capacitor (internal component of powerpack) is released, it travels via the primary wire to the primary winding of the ignition coil. The voltage flowing thru the primary winding creates an electro-magnetic force which acts on the coil secondary windings and this basically act as a step-up transformer and boosts the voltage to 25-35kv (depending on application). As the voltage spikes and falls, RFI (radio frequency interference) is created. The suppressor plugs "absorb" this spike. If the RFI isn't dealt with, the energy from it can interfere with the operation of the ignition system, due to the close proximity of all the components. It can cause a hi-speed miss or make the engine go into SLOW.<br /><br />-John