Mercury - Quicksilver 816761Q8 Spark Plug Wire Kit Inline 6-Cylinder MerCruiser Engines Points Ignition 816761Q8. Overview. If your old inline-six MerCruiser is starting to sputter or miss, new plug wires might be just what it needs. The Quicksilver 816761Q8 Spark Plug Wire Kit brings back smooth ignition and steady performance for 6-cylinder MerCruiser engines (1963-1981) equipped with conventional points ignition systems.. This OEM set includes all six wires, each molded, measured, and cut to