Ignition Sensor for Mercruiser Thunderbolt Electronic Ignition Systems.
It is for all Mercruiser Thunderbolt Distributors with nut or bullet connections used on V6 & V8 applications.
Replaces Merc. # 87-861780Q4, 87-861780A2
Your current sensor may only have two wires or terminals, this item has improved circuitry which incorporates a separate ground for improved performance and reliability.
Replaces Ring terminal sensor or bullet end connectors.
Troubleshoot This Part with these Instructions