Tuneable Mechanical Advance Kit with Silver Spring For Big Twin 1970-79 & Sportster 1971-79 Pack of 10

Weight: 0.02 Designed to outperform and outlast anything out there, this tuneable mechanical advance unit is the finest available. It features a heat treated stainless steel base, pre-lubricated heat treated weights and three sets of color coded springs that allow you to select three different advance curves to meet your engine's requirements. Tuneable Features: Black Spring - Allows full advance @ 1400 RPM (same as OEM) Silver Spring - Allows full advance @ 2000 RPM Gold Spring - Allows full advance @ 2600 RPM Advantages: Eliminating spark knock and detonation means longer engine life and more low end horsepower and torque. The only mechanical advance unit kit that allows you to adjust your advance curve. A must if you have performance work done. Even minor performance changes can require a different advance curve. V-FACTOR Silver Spring allows full advance @ 2000 RPM Fits Big Twin 1970-1979 & Sportster 1971-1979 Package of 10, (Imported)