🏷️ Basic Information

Make:

Harley-Davidson

Model:

FLSTF Fat Boy

Year:

2015

Model Code:

FLSTF

Generation:

Softail

👋 Introduction

Market Segment:

Cruiser Motorcycle

Target Audience:

Harley-Davidson owners, independent repair shops, and motorcycle enthusiasts seeking detailed maintenance and repair information.

Competitor Manuals:

Generally considered superior to aftermarket generic manuals due to factory-level detail and accuracy.

Features:

Factory-authorized procedures, detailed diagrams, comprehensive troubleshooting guides, and accurate specifications.

📋 Manual Details

Systems Covered:

Engine, Transmission, Drivetrain, Fuel System, Ignition System, Electrical System, Lighting, Instruments, Chassis, Suspension, Brakes, Wheels, Tires, Frame, Bodywork, Controls, Maintenance, Troubleshooting, Diagnostics, Specifications

Page Count:

Extensive (typically 500+ pages for full service manuals)

Manual Type:

Full Service Repair Manual

Language:

English

Format:

Digital (likely PDF, but can be printed)

📖 Manual Coverage

Engine System:

Detailed disassembly, inspection, assembly, and overhaul of the Twin Cam 103 powertrain, including cylinder heads, cylinders, pistons, connecting rods, crankshaft, camshafts, valve train, oil pump, and lubrication system.

Fuel System:

Coverage of Electronic Sequential Port Fuel Injection (ESPFI) system, throttle body, fuel injectors, fuel pump, fuel filter, fuel lines, and fuel tank servicing.

Ignition System:

Ignition module, crank position sensor, spark plugs, ignition coils, and troubleshooting ignition performance issues.

Transmission Drivetrain:

Service and repair of the 6-speed Cruise Drive transmission, clutch assembly, primary drive, and belt final drive, including gear inspection, bearing replacement, and chain tensioner adjustments.

Electrical System:

Complete wiring diagrams, starter system, battery service, charging system (stator, regulator/rectifier), lighting circuits (headlight, taillight, signals), horn, and accessory wiring.

Chassis Suspension:

Front fork service (fork seals, oil change), rear shock absorber inspection and replacement, swingarm bearings, and steering head bearing maintenance.

Brake System:

Front and rear brake caliper service, master cylinder overhaul, brake line replacement, hydraulic fluid bleeding, and ABS system diagnostics (if equipped).

Bodywork Controls:

Fender removal and installation, fuel tank mounting, seat service, handlebar replacement, control cable adjustments (throttle, clutch), and rider foot controls.

Maintenance Procedures:

Scheduled maintenance tasks, oil and filter changes, air filter replacement, spark plug replacement, drive belt inspection and adjustment, brake fluid flush, and battery maintenance.

Troubleshooting Diagnostics:

Step-by-step diagnostic procedures for common running issues, electrical faults, starting problems, and performance anomalies, often utilizing diagnostic codes.

Repair Procedures:

Detailed instructions for component disassembly, repair, reassembly, and adjustment for all major systems, including engine rebuilds and transmission overhauls.

Technical Specifications:

Torque specifications for critical fasteners, fluid capacities, electrical component specifications, engine clearances, and dimensional data.

Depth Of Coverage:

Comprehensive, covering everything from basic rider maintenance to full engine and transmission rebuilds, suitable for both novice DIY mechanics and professional technicians.

📊 Manual Specifications

File Format:

PDF (Searchable text, printable pages)

Print Quality:

High-resolution diagrams and text, ensuring clarity for all instructions.

Binding Type:

Not applicable for digital format; if printed, typically spiral-bound or perfect-bound for lay-flat usability.

Paper Type:

Not applicable for digital format; if printed, typically heavy-stock, coated paper suitable for workshop environments.

⚙️ Engine Specifications

Engine Type:

Air-cooled, Twin Cam 103B V-twin

Displacement:

1690 cc (103 cubic inches)

Bore X Stroke:

3.875 in. x 4.375 in. (98.4 mm x 111.1 mm)

Compression Ratio:

9.0:1

Horsepower:

Approx. 75 HP (Varies slightly based on tuning and exhaust)

Torque:

Approx. 98 ft-lb @ 3,000 RPM (Varies slightly based on tuning and exhaust)

Fuel Delivery:

Electronic Sequential Port Fuel Injection (ESPFI)

Fuel Type:

Premium Unleaded Gasoline (91 octane or higher recommended)

🔧 Transmission

Transmission Type:

6-speed Cruise Drive

Clutch Type:

Clutch, wet, multi-plate

Primary Drive:

Patented, cradle-mounted, primary chain drive; ratio 1.340

Final Drive:

Belt, 25mm, 140T

Gear Ratios:

1st: 9.315, 2nd: 6.407, 3rd: 4.774, 4th: 3.790, 5th: 3.231, 6th: 2.790

📐 Dimensions

Length:

93.9 in. (2385 mm)

Seat Height Laden:

26.1 in. (663 mm)

Ground Clearance:

4.1 in. (104 mm)

Wheelbase:

64.2 in. (1630 mm)

Rake:

32°

Trail:

5.2 in. (132 mm)

Dry Weight:

670 lbs. (304 kg)

Gross Vehicle Weight Rating Gvwr:

1,010 lbs. (458 kg)

Payload Capacity:

340 lbs. (154 kg)

Fuel Capacity:

5.0 gal. (18.9 L)

🛡️ Safety Features

Crash Test Ratings:

N/A (Motorcycles are not subjected to standard automotive crash testing.)

Braking System:

Hydraulic disc brakes, front and rear. Optional ABS (Anti-lock Braking System) available.

Lighting:

Halogen headlight, LED taillight and brake light, amber incandescent front and rear turn signals.

Frame Construction:

Steel frame and chassis.

Mirrors:

Chrome, teardrop mirrors.

💡 Technology Features

Audio System:

Not typically equipped with a factory-installed audio system on the FLSTF Fat Boy model. Aftermarket options are common.

ABS:

Optional Anti-lock Braking System (ABS) available on certain configurations.

Diagnostics:

Diagnostic port (e.g., for digital technician) for reading fault codes and monitoring engine parameters.

🔧 Maintenance

First Service Mileage:

1,000 miles (1,600 km)

Subsequent Service Intervals:

Every 5,000 miles (8,000 km) or 12 months, whichever comes first.

Engine Oil Type:

Harley-Davidson SYN3 Synthetic or equivalent SAE 20W50 motorcycle oil meeting HD-360 specifications.

Engine Oil Capacity:

3.7 U.S. qt. (3.5 L)

Primary Chain Case Oil Type:

Harley-Davidson Formula+ or equivalent SAE 50 motorcycle oil.

Primary Chain Case Oil Capacity:

1 U.S. qt. (0.95 L)

Transmission Oil Type:

Harley-Davidson Formula+ or equivalent SAE 75W-90 Synthetic Transmission Lubricant.

Transmission Oil Capacity:

2.0 U.S. pt. (0.95 L)

Brake Fluid Type:

DOT 4 brake fluid.

Common Wear Items:

Clutch plates, brake pads, wheel bearings, fork seals, and drive belt.

Potential Electrical Issues:

Corrosion on connectors, charging system component failures (stator, regulator).

Engine Considerations:

While Twin Cam engines are generally robust, regular oil changes and proper maintenance are crucial for longevity. Valve adjustments may be required at specified intervals.

📚 Vehicle History

Brand Established:

1903

Brand Philosophy:

Custom styling, V-twin engines, and a distinct riding experience.

Fat Boy Introduction:

First introduced in 1990, the Fat Boy quickly became an icon for its distinctive styling, including its wide front end, solid-disc aluminum wheels, and wide whitewall tires.

Fat Boy Styling Cues:

Fat custom styling, large headlamp, distinctive handlebar, and robust overall appearance.

Manufacturing Location:

United States (Various Harley-Davidson plants)

🏆 Awards & Recognition

Model Recognition:

The Fat Boy is a consistently popular model and often recognized for its iconic styling and V-twin performance within the cruiser segment.

Customer Satisfaction:

Generally high, reflecting Harley-Davidson's strong brand loyalty and the model's appeal.