Replaces part # 84-816761Q16, 84-813720A11, 503751, 18-8810-1
This wire set meets or exceeds OEM specifications.
Fits: MerCruiser 4.3L engines from 1985-93 with Thunderbolt ignition systems
When should you replace your wires? - Plug wires or boots are cracked, dried out, or torn / Engine is difficult to start, espcially in cold or damp weather / Fuel economy has decreased / Engine stalls or idles rough / Poor acceleration