Mercury - Quicksilver 8M6001254 Rotor Delco EST Ignition System Marine-Grade Composite 8M6001254. Overview. There's a kind of quiet reassurance that comes from knowing your ignition system fires exactly when it should. It is the kind of confidence you feel when you ease your MerCruiser engine away from the dock and hear that steady, even rhythm. The Quicksilver 8M6001254 Rotor helps keep that reliability alive. Built for General Motors 4-cylinder engines equipped with Delco Electronic Spark Timi