Market Position:
The Harley-Davidson Fat Boy is a cornerstone of the brand's cruiser line, representing iconic styling and robust V-twin performance. This manual serves owners and technicians of a popular and enduring model within the cruiser segment.
Competitive Analysis:
Competes with other large-displacement cruisers from manufacturers like Indian Motorcycle, Victory Motorcycles (historically), and Japanese brands offering similar styling and displacement.
Key Features:
Distinctive wide front tire, FL-style tank and fenders, chrome-laden powertrain and exhaust, classic styling cues. Covered period includes early EFI integration and evolution of the Twin Cam 88 engine.
Manual Purpose:
To provide comprehensive, step-by-step instructions for the maintenance, troubleshooting, and repair of Harley-Davidson FLSTF and FLSTFI Fat Boy motorcycles manufactured between 2000 and 2006.
Systems Covered:
Engine (1450cc Twin Cam 88), Fuel System (Carbureted and EFI), Ignition System, Electrical System, Transmission (5-speed), Clutch, Drivetrain, Suspension (Front and Rear), Brakes (Front and Rear), Wheels and Tires, Frame, Bodywork, Instruments, Controls, Lighting, Cooling System, Lubrication System, Chassis Components
Procedures Included:
Routine maintenance, detailed disassembly and reassembly instructions, troubleshooting guides, diagnostic procedures, component testing, torque specifications, wiring diagrams, exploded views, service bulletins, performance tuning
Technical Depth:
Comprehensive, suitable for professional technicians and advanced DIY enthusiasts. Covers everything from basic fluid changes to complete engine and transmission overhauls.
Troubleshooting Guides:
Detailed diagnostic flowcharts and step-by-step procedures for common problems related to engine, ignition, fuel system, electrical system, and more.
Diagnostic Procedures:
Covers the use of diagnostic tools and methods for EFI models (FLSTFI), including understanding error codes and live data interpretation.
Wiring Diagrams:
Detailed, high-quality wiring diagrams illustrating the entire electrical system, essential for troubleshooting electrical faults.
Exploded Views:
Exploded views of all major assemblies to aid in identification of parts and understanding of assembly order.
Primary Engine:
Harley-Davidson Twin Cam 88 (1450cc)
Bore X Stroke:
3.75 in. x 4.00 in. (95.25 mm x 101.6 mm)
Compression Ratio:
8.8:1 (typical)
Horsepower:
Approx. 65-70 HP (at rear wheel, stock tuning)
Torque:
Approx. 85-90 ft-lbs (at rear wheel, stock tuning)
Fuel System:
Carbureted (Keihin CV40 for FLSTF) and Electronic Fuel Injection (EFI for FLSTFI)
Ignition System:
Electronic Ignition with single fire ignition coil
Oil Type:
Harley-Davidson 20W-50 or equivalent motorcycle-specific oil
Oil Capacity:
Approximately 4 US quarts (3.8 L) with filter change
Cooling System:
Air-cooled (oil cooling via engine oil)
Transmission Type:
5-speed Cruise Drive constant mesh, helical gear
Gear Ratios:
Refer to manual for specific ratios (typically: 1st: 9.34, 2nd: 6.54, 3rd: 4.77, 4th: 3.78, 5th: 3.17)
Transmission Fluid Type:
Harley-Davidson Genuine Formula Transmission Oil or compatible heavy-duty gear oil
Clutch Type:
Wet, multi-plate, diaphragm spring
Primary Drive:
Duplex chain
Length:
Approx. 93.0 inches (2362 mm)
Width:
Approx. 37.0 inches (940 mm) at handlebars
Height:
Approx. 49.5 inches (1257 mm) at handlebars
Dry Weight:
Approx. 630 lbs (286 kg)
Gross Vehicle Weight Rating:
Refer to VIN sticker for specific rating
Payload Capacity:
Refer to VIN sticker for specific rating
Front Tire Size:
130/90B16 67H (FLSTF model specific wide tire)
Rear Tire Size:
130/90B16 67H (standard)
Wheel Bolt Pattern:
N/A (Harley-Davidson solid disc wheels with bearing hubs)
Safety Ratings:
Motorcycles are not rated by NHTSA or IIHS in the same way as cars. Safety depends on rider skill and adherence to safe riding practices.
Active Features:
Disc brakes front and rear, handlebar-mounted controls for responsive steering and braking.
Passive Features:
Heavy-duty frame construction, rider footboards for stability.
Infotainment:
Base models typically feature analog instrumentation with a speedometer, tachometer, fuel gauge, and indicator lights. Optional fairings or accessory radios may be present on some models.
Driver Assistance:
ABS (Anti-lock Braking System) was an optional feature on some models within this year range. Refer to specific vehicle VIN for ABS presence.
Connectivity:
No integrated smartphone connectivity or Bluetooth in base models of this era.
Service Intervals:
Refer to manual for specific intervals. Typical services include: 1,000 miles (1600 km) - initial check-up, oil change. 5,000 miles (8000 km) - engine oil and filter change, inspection. 10,000 miles (16000 km) - spark plugs, transmission fluid change, primary chain case oil change, clutch adjustment.
Engine Oil Specification:
Harley-Davidson 20W-50 Syn3 or equivalent motorcycle oil.
Transmission Fluid Specification:
Harley-Davidson Formula + Transmission & Primary Chaincase Lubricant or equivalent.
Primary Chaincase Oil Specification:
Harley-Davidson Formula + Transmission & Primary Chaincase Lubricant or equivalent.
Brake Fluid Specification:
DOT 4 (for models with ABS, if equipped, or specified in manual)
Known Issues:
Cam chain tensioner wear (especially early Twin Cam 88 models), potential oil leaks, exhaust pipe flange leaks, starter drive issues. The manual will detail inspection and replacement procedures for these and other common wear items.
Oil Filter Part Number:
Harley-Davidson 63731-98, or aftermarket equivalents.
Air Filter Part Number:
Refer to manual for model-specific part numbers (e.g., 29451-99 for some).
Spark Plug Type:
Typically Harley-Davidson H-D 10R or equivalent (e.g., NGK DCPR7E)
Torque Specifications:
Comprehensive torque specifications for all critical fasteners, including engine components, suspension, brakes, and bodywork.
Brand Heritage:
Harley-Davidson, founded in 1903, is synonymous with American motorcycle culture, known for its V-twin engines, distinctive styling, and a strong rider community.
Model Evolution:
The Fat Boy was introduced in 1990 and quickly became an icon. The FLSTF is the carbureted version, while the FLSTFI (Fuel Injection) was introduced later in the product cycle to meet emissions standards and improve performance consistency. The 2000-2006 period saw the transition and refinement of the Twin Cam 88 engine platform.
Production Years:
FLSTF: 1990-Present (with various engine updates). FLSTFI: Introduced later (e.g., 2001/2002) for EFI models.
Manufacturing Locations:
United States (various Harley-Davidson facilities)
Model Introduction Year:
1990 (for the Fat Boy model line)
