Solenoid | Sierra 18-5808 Sierra Solenoid | 18-5808 12V isolated base starter solenoid for many Johnson, Evinrude, and Mercury outboard motors. Isolated base 12 volt 4 terminal posts Replaces Mercury 47886T, 47886 Replaces OMC 586180, 582708, 395419, 380095, 383622, 389493, 389398 | Replaces Mallory 9-15104