Mercury - Distributor Cap Kit Ignition System Component PBT/PET Composite & Brass Inserts 898253T28. Overview. When you turn the key on a MerCruiser 4.3L MPI, you expect that clean, confident spark that brings the engine to life fast, smooth, and steady. But as every boater knows, ignition components age quietly. You may not notice the slow decline until the idle gets a little rough or the engine hesitates under load. The Quicksilver 898253T28 Distributor Cap Kit restores that crisp ignition fee