Mercury - Quicksilver 819503A1 Solenoid Kit Mercury 65-125HP Carbureted TwoStroke Outboards 819503A1. Overview. If your outboard hesitates or won't crank when you turn the key, the starter solenoid is usually the first place to look. The Mercury 819503A1 Solenoid Kit is a direct OEM replacement made for Mercury 65-125HP carbureted TwoStroke outboards. It delivers clean, steady power to the starter every time you fire up the engine.. This solenoid is built tough for marine life - sealed tight aga