The classic HD configuration could be under threat.
Harley-Davidson no longer produces any models with carburetors. While innovation is seldom met with universal approval — chain- to belt-drive being a prime example — those who were skeptical of the phasing in of electronic fuel injection, or EFI, had at least one sound reason for disapproval: Faulty carburetors can often be diagnosed and repaired on the side of the road, while narrow-band O2 sensors and a sealed “black box” brain cannot.
Standard Harley Carbs
Motorcycling lore has it that the very first machine produced by William Harley and Arthur Davidson used a modified tomato can for a carburetor. This was followed by units produced, in sequence, by Schebler, Linkert, Tillotson, Zenith-Bendix and Keihin. Of course, numerous aftermarket companies have produced countless carburetors to fit Harley-Davidson motorcycles since racing and personalization began. The Keihin CV CVK 40 was fitted to Sportsters from 1988 and to the big twins from 1990. Given the phasing out of carburetors, then, the CVK 40 is probably the last carburetor that will ever be fitted to a production Harley.
The Last Years of the Harley-Davidson Carburetor
Throughout the years, Harley-Davidson paired a carburetor with every engine the company produced, ranging from the older knucklehead, panhead and shovelhead engines to the newer Evolution and Twin Cam engines. However, fuel injection was offered as an option for Harley-Davidson’s popular FL-series Touring motorcycles starting with the 1996 model year, but in 2007 became standard equipment on all Twin Cam engine models, which now included all Touring, Dyna and Softail models. Only the Sportster series remained old school and retained the carbureted Evolution engine. For the 2008 model year, that series also lost carburetors in favor of Harley-Davidson’s Electronic Sequential Port Fuel-Injection system. The era of the carburetor had ended.
Importance of Accurate Information
Many purists, custom builders and hobbyists keen on nostalgia or emulating carb-fueled race bikes retrofit carburetors to engines intended to run on EFI. For this to be practical, it is important to know which model and year of the engine ran with traditional aspiration, so that the retrofitted carb can be worked on properly. For instance, somebody intending to convert a 2008 FXST to carb would need the Service Manual and the Parts Manual for the last year that Softails were made before EFI became standard; in that instance, it would be model year 2007.
Carburetors vs. Fuel Injection
Harley-Davidson, as well as the people who ride the company’s products, is resistant to change. That said, there are pros and cons to each side of the carb vs. EFI debate. New generations of Harley purchasers are by definition younger, making them more tech-savvy and less resentful of change. While carburetion is a simpler system and there are no electronics packages to require expert mechanical attention, sophisticated, well-calibrated EFI systems generate more peak power through better fuel management. The phasing out of carburetors was, at least in part, due to pressure exerted on the factory by the Environmental Protection Agency. Fuel-air mixture is far more tightly controlled by fuel injection, resulting in decreased emissions. Based on this factor alone, EFI is here to stay.