Mercury - Quicksilver Ignition Tune-Up Kit Ignition System Component Mallory Conventional 5090Q1. Overview. When your classic MerCruiser V8 starts to lose its edge - rough idle, weak spark, sluggish power - a good tune-up can bring it right back to life. The Mercury Marine 5090Q1 Quicksilver Ignition Tune-Up Kit gives you everything you need to refresh the ignition on marinized GM or Ford V8 MerCruiser engines equipped with Mallory conventional ignition systems. This OEM kit restores strong spar