Switch Box Mercury Mariner | CDI 114-4911 CDI Electronics Mercury Mariner Switch Box | 114-4911 High performance replacement ignition pack for various 20 HP & 40 HP Mercury/Mariner 2 cylinder outboard engines. CDI Electronics outboard ignition pack Fits Mercury and Mariner 20 HP model 200 2 cylinder outboard engines from 1973 to 1977 with serial number range 3537531-4403786 Fits Mercury and Mariner 40 HP model 402 outboard engines from 1972 to 1977 with serial number range 3336258-4860102 Fits Mercury and Mariner 40 HP 2 cylinder outboard engines from 1975-1981 with serial number range 4117710-5823917 CDI determines the most common causes of component failure and designs their replacements to be better than the original Replaces Mercury 18495A 9, 18495A14, 18495A16, 18495A17, 18495A20, 18495A21, and 18495A30 Replaces Sierra 18-5786 & 18-5787