Mercury - Tachometer 8000 RPM SmartCraft Analog Gauge White Face 110 mm 79-8M0069431. Overview. The Mercury Tachometer (79-8M0069431) delivers precise RPM readings up to 8000 RPM, making it ideal for performance Mercury engines. The white face, black numerals, and glass lens make it sharp, easy to read, and perfectly matched to Mercury's clean OEM styling. It fits a standard 110 mm (4-3/8") dash opening and connects directly to SmartCraft-capable systems for dependable, real-time engine data at