Fat Boy Injection

2001 Harley-Davidson Fat Boy Injection Technical Analysis & Specification Breakdown

Engineered by Harley-Davidson for the custom - cruiser motorcycle segment, the 2001 Harley-Davidson Fat Boy Injection relies on a 1449 cc (88.4 cu in) air-cooled v2, four-stroke powerplant. In factory specification, peak output is rated at 64 HP (46.7 kW) at 5,300 rpm while maximum torque reaches 105 Nm (77.4 lb-ft) at 3,000 rpm, transferring power to the rear wheel through a 5-speed gearbox and belt final drive. With a specific output of 44.2 HP per liter and a 2,300 rpm working window between peak torque (3,000 rpm) and peak power (5,300 rpm), the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.

On the scales, the Fat Boy Injection measures 320 kg (705 lbs) wet (curb), translating to a power-to-weight ratio of 0.2 HP/kg (5 kg per horsepower). Rider ergonomics and chassis geometry center around a 647 mm (25.5 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,638 mm (64.5 in) wheelbase engineered for planted straight-line stability. The 18.9-liter (5 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 173 km/h (107 mph).