Model:
FLSTF Softail Fat Boy
Production Years Covered:
1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999
Target Audience:
Harley-Davidson FLSTF Softail Fat Boy owners, independent motorcycle mechanics, and custom bike builders seeking detailed service information.
Value Proposition:
Provides a complete factory-level resource for maintenance, repair, and diagnostics, offering significant cost savings compared to dealership service.
Authenticity:
Represents the official factory service documentation, ensuring accuracy and completeness.
Accessibility:
Instant download PDF format allows for immediate access to critical repair information.
Comprehensiveness:
Covers all aspects of the motorcycle, from routine maintenance to major overhauls.
Engine Mechanical:
Complete overhaul, disassembly, assembly, tuning, and troubleshooting of the Evolution V-Twin engine.
Fuel System:
Carburetor service (Keihin CV), fuel tank, fuel lines, fuel pump (if applicable), and emissions control systems.
Ignition System:
Ignition module, spark plugs, ignition coils, timing, and troubleshooting.
Electrical System:
Wiring diagrams, battery, charging system (alternator, regulator), starter motor, lighting, switches, and accessories.
Transmission Drivetrain:
Primary drive, clutch, transmission (5-speed constant mesh), drive belt, final drive, and related adjustments.
Suspension:
Front fork (telescopic), rear shock absorbers, swingarm, and related components.
Brakes:
Front and rear disc brakes, hydraulic system, caliper service, master cylinders, and brake fluid specifications.
Wheels Tires:
Wheel bearing service, tire inspection, replacement, and pressure recommendations.
Frame Chassis:
Frame inspection, steering head bearing service, and general chassis components.
Bodywork Fenders:
Fender removal/installation, fuel tank removal/installation, seat, and other body panels.
Controls Cables:
Throttle cables, clutch cable, brake cables, and control lever adjustments.
Maintenance:
Routine servicing, oil changes, filter replacements, spark plug replacement, chain/belt adjustment, brake system checks.
Troubleshooting:
Systematic diagnostic procedures for common and uncommon problems across all major vehicle systems.
Repair:
Detailed step-by-step repair instructions for component overhauls, replacements, and adjustments.
Disassembly Assembly:
Complete guidance on dismantling and reassembling engine, transmission, and other major components.
Rebuilds:
Instructions for complete engine and transmission rebuilds.
Depth Level:
Comprehensive (covers everything from basic maintenance to full engine and transmission rebuilds, including diagnostics and specifications).
Digital Format:
PDF (Portable Document Format)
Searchability:
Likely text-searchable PDF, allowing for quick information retrieval.
Image Quality:
High-resolution images, diagrams, and schematics typical of factory service manuals.
Binding:
N/A (Digital Download)
Paper Quality:
N/A (Digital Download)
Licensing:
No expiry dates mentioned, implying perpetual access upon purchase.
Engine Family:
Harley-Davidson Evolution (Evo) V-Twin
Engine Type:
Air-cooled, OHV, 45-degree V-twin
Displacement:
1340 cc (81.8 cubic inches)
Bore X Stroke:
3.497 in. x 4.250 in. (88.8 mm x 107.95 mm)
Compression Ratio:
8.2:1 (typical)
Horsepower Approximate:
60-70 HP (estimated, varies by specific model year tuning)
Torque Approximate:
75-85 ft-lbs @ 3200 RPM (estimated)
Carburetor:
Keihin CV (Constant Velocity) 40mm
Fuel Type:
Unleaded gasoline, minimum 87 octane
Oil Type:
Harley-Davidson Genuine V-Twin Oil SAE 20W-50 (or equivalent)
Oil Capacity:
Approx. 3.0 US quarts (2.8 Liters) with filter change.
Transmission Type:
5-speed, constant mesh, manual
Primary Drive:
Duplex chain, wet clutch
Clutch Type:
Wet, multi-plate
Gear Ratios:
Specific gear ratios will be detailed within the manual.
Transmission Fluid:
Harley-Davidson Genuine Formula + Transmission Oil (or equivalent SAE 80W-90 GL-5 gear oil)
Transmission Fluid Capacity:
Approx. 1.0 US quart (0.95 Liters)
Wheelbase:
Approx. 64.5 inches (1638 mm)
Seat Height:
Approx. 26.5 inches (673 mm)
Dry Weight:
Approx. 610 lbs (277 kg)
Gross Vehicle Weight Rating:
N/A (Specific GVWR not typically published for motorcycles, focus on payload capacity)
Fuel Capacity:
Approx. 4.0 US gallons (15.1 Liters)
Safety Certification:
Meets all applicable Federal Motor Vehicle Safety Standards (FMVSS) for motorcycles of its era.
Braking System:
Dual hydraulic disc brakes (front and rear) providing strong stopping power.
Lighting:
Halogen headlamp, taillight, stop light, and turn signals for visibility.
Frame Construction:
Robust steel frame designed for stability and rider safety.
Ergonomics:
Designed for rider comfort and control.
Audio System:
Typically no integrated infotainment system on stock models of this era; aftermarket options available.
ABS:
Anti-lock Braking System (ABS) was not a standard or widely available option on this model during these years.
Usb Ports:
No factory USB ports; aftermarket solutions required for device charging.
Dashboard:
Analog speedometer, tachometer (optional on some trims), odometer, trip meter, and indicator lights.
Oil Change Interval:
Every 2,500 miles or 4 months (whichever comes first).
Primary Chain Tensioner Check:
Inspect at 1,000 miles, then every 5,000 miles. Replace if worn (often an upgrade to hydraulic tensioner recommended by 1999).
Spark Plug Replacement:
Every 10,000 miles or as needed.
Belt Drive Tension Check:
Check periodically per manual instructions (typically at 1,000-mile intervals).
Engine Oil Specification:
Harley-Davidson Genuine V-Twin Oil SAE 20W-50
Transmission Oil Specification:
Harley-Davidson Genuine Formula + Transmission Oil (SAE 80W-90 GL-5)
Brake Fluid Specification:
DOT 4 Hydraulic Fluid
Primary Chain Case Oil:
Harley-Davidson Genuine Primary Chaincase Lubricant (or equivalent ATF Dexron III)
Primary Chain Tensioner:
The original spring-loaded primary chain tensioner is known to wear out and require replacement, often around 15,000-30,000 miles. Hydraulic upgrade is common.
Carburetor Tuning:
Keihin CV carburetor may require periodic adjustment or re-jetting for optimal performance, especially with aftermarket exhaust or air cleaner modifications.
Rear Brake Pads:
Can wear faster than front pads depending on riding style.
Wiring Harness Integrity:
As bikes age, inspect wiring for chafing or corrosion, particularly around the handlebars and under the seat.
Brand Legacy:
Harley-Davidson boasts a long and iconic history in motorcycle manufacturing, synonymous with American cruiser culture.
Softail Platform:
The Softail chassis, introduced in 1983, mimics the appearance of a hardtail frame while incorporating a hidden rear suspension system for improved ride comfort.
Fat Boy Introduction:
The Fat Boy (FLSTF) model, introduced in 1990, quickly became an icon with its distinctive styling, including solid aluminum disc wheels, wide handlebars, and fat tires.
Evolution Engine:
The 1340cc Evolution engine, introduced in 1984, replaced the Shovelhead and Panhead engines, offering improved reliability and performance.
Manufacturing Location:
York, Pennsylvania and Milwaukee, Wisconsin, USA (typical for Harley-Davidson during this period).
