Mercury - SC1000 Tachometer 5000 RPM (No Logo) SmartCraft Analog Gauge White Face 85 mm 79-8M0135658. Overview. The Mercury SC1000 5000 RPM Tachometer (79-8M0135658) gives you clean, accurate RPM readings and a simple, modern look. This version features a white face with no logo, a clear glass lens, and fits a standard 85 mm (3-3/8 in.) dash opening. It's built for SmartCraft-equipped boats and supports both RPM- and speed-based SmartTow functions. Depending on your engine setup and available se