ARCO Marine Outboard Solenoid f/Mercury/Force w/Isolated Base

The ARCO Marine Outboard Solenoid f/Mercury/Force w/Isolated Base is the starter solenoid every Mercury and Force outboard owner should keep on hand—or already have installed. After decades on the water, any boater knows that solenoid failure is one of the most common electrical gremlins that can strand you far from the ramp. This 12-volt solenoid bridges the gap between your battery's cranking power and your starter motor, completing the circuit that fires your engine to life. When it fails, your boat won't turn over, no matter how good your battery is or how hard you crank the key.

ARCO's isolated-base design separates the solenoid's mounting surface from its electrical ground, preventing unwanted current leakage through the engine block and reducing corrosion—critical in salt and brackish water environments where galvanic attack eats components alive. The compact 3 x 3 x 4-inch footprint and lightweight 0.75-pound construction make installation straightforward in tight engine compartments. This unit is a direct replacement for Mercury part numbers 89-817109A1, 89-817109A2, and 89-817109A3, as well as Sierra 18-5834, ensuring exact OEM compatibility without guesswork.

Boat owners running Mercury or Force outboards—especially those in saltwater or high-humidity climates—will extend engine reliability and eliminate the risk of being stranded by keeping this replacement solenoid in the spare parts locker or installing it as preventive maintenance. Professional mechanics and weekend anglers alike trust ARCO Marine's reputation for delivering OEM-quality electrical components that perform year after year. Installation requires basic mechanical skills and a socket wrench; consult your engine manual for exact terminal routing and mounting bolt torque specifications.