Mercury - Distributor Cap Kit MPI Ignition System Composite Construction 8M0061335. Overview. When you spend your weekends on the water, you can feel when your engine is running right. There's a certain steadiness to it-a rhythm that settles in as you push through open channels or ease into the marina at sunset. Your ignition system is at the heart of that feeling, and the distributor cap plays a bigger role than most folks realize. The Mercury 8M0061335 Distributor Cap Kit gives you that quiet