Mercury - Quicksilver 816761Q9 Spark Plug Wire Kit V8 MerCruiser Engines (Ford & GM) Points & Thunderbolt Ignition 816761Q9. Overview. Reliable spark makes all the difference in how your boat performs. The Quicksilver 816761Q9 Spark Plug Wire Kit keeps classic V8 MerCruiser engines - built by Ford or General Motors - running strong and smooth. Designed for points ignition systems (1963-1982) and Thunderbolt ignition systems (1968-1976), this OEM wire set restores the clean, consistent ignition t