Harley-Davidson has used the 40mm Keihin constant velocity (CV) carburetor since 1988 on Sportsters and introduced them in 1990 on the Big Twins. The 1988 model differed from the 1989-and-later carbs ...
ATV Carburetor Adjustment involves tuning your ATV’s carb for maximum performance. How do I know my jetting is off? My ATV bogs down a lot, is jetting to blame? I have performance parts, what now?