Mercury - Quicksilver 816761Q5 Spark Plug Wire Kit 4-Cylinder MerCruiser Engines Points Ignition 816761Q5. Overview. If your old MerCruiser hesitates when you turn the key or idles rough after warm-up, it's probably time for new plug wires. The Quicksilver 816761Q5 Spark Plug Wire Kit gives your 4-cylinder MerCruiser (1963-1995) the clean, consistent spark it needs to run like it should.. Built for points-style ignition systems, these OEM wires fit exactly as the originals did. Each lead is cut