🏷️ Basic Information

Make:

Harley-Davidson

Model:

FLSTFI Fat Boy

Year:

2006

Sub Model:

FLSTFI

Vin Code:

1HD1

👋 Introduction

Description:

The Harley-Davidson FLSTFI Fat Boy is an iconic cruiser known for its distinctive styling, comfort, and powerful V-twin engine. It represents a blend of classic design with modern V-twin technology.

Competitors:

Competes with other large-displacement cruisers from manufacturers like Indian Motorcycles, Victory Motorcycles (discontinued), and custom-built choppers.

Styling:

Distinctive wide front tire, chrome detailing, teardrop fuel tank, and flowing lines.

Engine:

Torque-rich Twin Cam 88B engine, designed for smooth operation with internal counterbalancers.

📋 Manual Details

Manual Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

Coverage Scope:

All Models/Variants of Harley-Davidson FLSTFI Fat Boy 2006

Page Count:

Estimated 500-700 pages (typical for this era of HD service manuals)

📖 Manual Coverage

Engine Mechanical:

Engine assembly, disassembly, component inspection, tuning, lubrication system, cooling system (air-cooled).

Fuel System:

Fuel injection system (EFI - Delphi Electronic Fuel Injection), fuel pump, fuel filter, injectors, throttle body, EVAP system.

Ignition System:

Ignition module, spark plugs, ignition coils, timing.

Transmission Drivetrain:

Clutch assembly, 6-speed cruise drive transmission, primary drive, final drive belt, chain (if applicable to sub-model), gear ratios.

Electrical System:

Battery, charging system (stator, regulator/rectifier), starter motor, lighting system (headlight, taillight, turn signals, brake lights), wiring diagrams, fuses, relays, switches, horn.

Brakes:

Front and rear brake systems, master cylinders, calipers, brake pads, brake lines, brake fluid, parking brake.

Suspension Steering:

Front fork assembly (including oil changes and seal replacement), rear shock absorbers, steering head bearings, wheel bearings.

Frame Chassis:

Frame inspection, swingarm, axles, wheels, tires, handlebar, controls.

Bodywork Fittings:

Fenders, fuel tank, seat, fairings (if equipped), exhaust system, mirrors, foot controls, primary cover, transmission cover.

Maintenance:

Scheduled maintenance tasks, oil changes, filter replacements, lubrication points, belt tension adjustment, brake bleeding.

Troubleshooting:

Diagnostic procedures for common and uncommon issues, symptom-based troubleshooting guides, fault code diagnosis (if applicable).

Repair Rebuild:

Detailed step-by-step instructions for component removal, installation, and rebuilding of major systems.

Wiring Diagrams:

Comprehensive electrical schematics for accurate fault diagnosis and repair.

Depth:

Comprehensive; covers everything from routine maintenance to complete engine and transmission overhauls. Includes detailed torque specifications, clearances, and diagnostic procedures.

📊 Manual Specifications

File Type:

PDF

Searchability:

Typically text-searchable for quick information retrieval.

Print Quality:

High-resolution, suitable for printing individual pages or the entire manual.

Binding:

N/A (Digital PDF)

Paper:

N/A (Digital PDF)

⚙️ Engine Specifications

Engine Type:

Harley-Davidson Twin Cam 88B V-twin

Displacement:

1449 cc (88 cubic inches)

Bore X Stroke:

3.75 in. x 4.00 in. (95.25 mm x 101.60 mm)

Compression Ratio:

8.9:1

Cooling System:

Air-cooled

Valve Train:

Overhead valve (OHV), 2 valves per cylinder, pushrod actuated.

Horsepower:

Approx. 65-70 HP (manufacturer figures often not officially stated, based on dyno results)

Torque:

Approx. 85-90 ft-lbs @ 3500 RPM (manufacturer figures often not officially stated, based on dyno results)

Fuel Delivery:

Electronic Sequential Port Fuel Injection (ESPFI) - Delphi

Fuel Type:

Unleaded gasoline, minimum 91 octane (Research Octane Number - RON)

Oil Capacity:

4.0 US quarts (3.8 L) with filter change

Oil Type:

Harley-Davidson Syn3 Full Synthetic SAE 20W-50 or equivalent API SG certified, JASO FD certified.

🔧 Transmission

Type:

6-speed Cruise Drive Transmission

Primary Drive:

Gear drive, wet multi-plate clutch

Final Drive:

Belt drive, 140 tooth final belt, 32 tooth front pulley, 3.15:1 final drive ratio.

Clutch Type:

Hydraulically actuated, wet multi-plate

Transmission Fluid:

Harley-Davidson Formula+, SAE 80W-90 Hypoid Gear Oil, or SAE 85W-140 Hypoid Gear Oil.

📐 Dimensions

Length:

9.06 ft. (2760 mm)

Overall Width:

3.15 ft. (960 mm)

Wheelbase:

5.41 ft. (1650 mm)

Ground Clearance:

5.2 in. (132 mm)

Seat Height:

27.0 in. (686 mm) unladen

Dry Weight:

694.0 lbs (314.8 kg)

Wet Weight:

Approx. 725.0 lbs (328.9 kg)

Fuel Capacity:

5.0 US gallons (18.9 L)

🛡️ Safety Features

Crash Safety Ratings:

Motorcycles are not typically subject to standardized crash testing like automobiles. Safety relies on rider skill and adherence to traffic laws.

Braking System:

Dual-piston caliper front brake, single-piston caliper rear brake with linked braking (integrated system in some configurations).

Lighting:

Halogen headlight, LED taillight, front and rear turn signals.

Frame Construction:

Steel frame and swingarm for robust construction.

Tire Configuration:

Wide front tire (130/90B16) for distinctive styling and stability, standard rear tire (150/80B16).

💡 Technology Features

Audio System:

Optional accessory audio systems available, not standard factory integrated infotainment on this model.

ABS:

Anti-lock Braking System (ABS) was an optional feature on some 2006 FLSTFI models; verify specific vehicle configuration.

Usb Ports:

No integrated USB ports on stock 2006 models; aftermarket solutions available.

🔧 Maintenance

Initial Service:

1,000 miles (1,600 km) or 6 months.

Subsequent Service:

Every 5,000 miles (8,000 km) or 12 months thereafter.

Engine Oil Change:

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

Transmission Fluid Change:

Every 10,000 miles (16,000 km) or 24 months.

Primary Chain Case Fluid Change:

Every 10,000 miles (16,000 km) or 24 months.

Engine Oil:

Harley-Davidson Syn3 Full Synthetic SAE 20W-50.

Transmission Fluid:

Harley-Davidson Formula+, SAE 80W-90 Hypoid Gear Oil, or SAE 85W-140 Hypoid Gear Oil.

Primary Chain Case Fluid:

Harley-Davidson Formula+ or SAE 20W-50 engine oil (non-synthetic is often recommended for primary).

Brake Fluid:

DOT 4 Brake Fluid.

Engine Cooling:

Overheating during prolonged slow-speed operation or in hot weather; potential issues with oil sumping.

Electrical:

Voltage regulator failure, stator failure, battery charging issues.

Transmission:

Clutch drag, difficulty shifting into neutral, occasional false neutrals.

Fuel System:

Potential for idle control issues with the EFI system, check engine light illumination.

Spark Plugs:

Inspect/Replace every 10,000 miles (16,000 km).

Air Filter:

Inspect every 5,000 miles (8,000 km), replace as needed.

Drive Belt:

Inspect tension and condition every 5,000 miles (8,000 km).

Brake Pads:

Inspect at every 5,000 mile service, replace as needed.

📚 Vehicle History

Brand History:

Harley-Davidson is one of the oldest motorcycle manufacturers in the world, with a rich history dating back to 1903. Known for its V-twin engines and cruiser lifestyle.

Fat Boy Introduction:

The Fat Boy model was introduced in 1990 and quickly became a cult classic, known for its bold styling and influence in popular culture.

Twin Cam Era:

The 2006 model features the Twin Cam 88B engine, which replaced the Evolution engine, offering increased displacement and a smoother ride.

Manufacturing Location:

Milwaukee, Wisconsin, USA, and Kansas City, Missouri, USA.

🏆 Awards & Recognition

Motorcycle Of The Year:

While specific model awards are less common for cruisers, the Fat Boy has consistently been recognized for its iconic design and cultural impact in motorcycle publications and enthusiast polls.