Mercury - Quicksilver Blue Wire Spark Plug Wire Kit V8 Inboard Ignition System Marine Grade 847701Q17. Overview. The Quicksilver 847701Q17 Blue Wire Spark Plug Wire Kit is built specifically for the V8 MerCruiser 454 Magnum MPI Horizon inboard engines from 1998. Each wire is made to the exact factory length and fitted with heavy-duty boots for a perfect fit. Designed by Mercury Marine, this set delivers a strong, consistent spark and holds up against the heat, moisture, and vibration that come w