Mercury - SC1000 Tach/Speed Kit 80 MPH Speedometer & 7K Tachometer Single Engine Black Face 79-8M0185920. Overview. The Mercury SC1000 Tach/Speed Kit (79-8M0185920) gives your single-engine boat a clean, factory-style SmartCraft gauge package. The kit includes an 80 MPH SC1000 speedometer and a 7000 RPM SC1000 tachometer, both with black faces, white numerals, and glass lenses for a sharp, easy-to-read finish. It's designed for single-engine SmartCraft setups and provides smooth, accurate perfor