🏷️ Basic Information

Make:

Harley-Davidson

Model:

FLH Series (Electra Glide, Road King, Ultra Classic)

Year:

2004

Engine Code:

Twin Cam 88 / Twin Cam 103

👋 Introduction

Market Segment:

Cruiser/Touring motorcycles.

Competitors:

Indian Motorcycles, Honda Gold Wing, Yamaha Royal Star/Venture, Kawasaki Vulcan.

Platform:

Evolution of Harley-Davidson's touring platform, building on the legacy of the Shovelhead and Evolution engines.

Target Audience:

Harley-Davidson owners, independent repair shops, enthusiasts looking for in-depth service and maintenance information.

📋 Manual Details

Primary Coverage:

Harley-Davidson FLH Series motorcycles equipped with Twin Cam 88 and Twin Cam 103 engines.

Estimated Pages:

Extensive (typically 700+ pages for a complete service manual)

Type:

Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine:

Twin Cam 88 & 103: Disassembly, assembly, inspection, performance tuning, fuel injection, ignition, lubrication, cooling, exhaust.

Transmission:

5-Speed Cruise Drive: Removal, installation, internal components, clutch, primary drive, final drive.

Chassis:

Frame, suspension (front fork, rear shocks), steering, wheels, tires, brakes (front and rear systems, ABS if equipped).

Electrical:

Wiring diagrams, charging system, starting system, lighting, instruments, ignition, fuel injection control, security system, audio system.

Bodywork:

Fairing, saddlebags, tour-pak, fenders, fuel tank, seating, trim components, mounting hardware.

Maintenance:

Scheduled maintenance intervals, fluid changes (engine oil, transmission oil, primary chaincase oil), filter replacements, lubrication points, brake system checks.

Troubleshooting:

Diagnostic procedures for common issues, symptom-based troubleshooting charts, error code interpretation.

Repair:

Step-by-step repair instructions for all major components, including engine overhauls, transmission rebuilds, brake caliper replacement, electrical component diagnosis and repair.

Special Tools:

Identification and usage of specialized Harley-Davidson tools required for various procedures.

Depth:

Comprehensive; covers basic maintenance to full engine and transmission rebuilds, including diagnostic procedures and specifications.

📊 Manual Specifications

Quality:

High-resolution, searchable PDF with clear diagrams and text.

Searchability:

Fully searchable text for quick access to specific information.

Printability:

Designed for easy printing of individual sections or the entire manual.

Binding Type:

N/A (Digital PDF Download)

Paper Type:

N/A (Digital PDF Download)

⚙️ Engine Specifications

Engine Family:

Harley-Davidson Twin Cam

Displacement Tc88:

88 cubic inches (1450cc)

Displacement Tc103:

96 cubic inches (1584cc) - Note: 103 typically refers to Big Bore kits or later models, but the manual likely covers conversions or factory variants for 2004. Clarification might be needed based on specific model/kit.

Configuration:

45-degree V-twin, air-cooled

Bore X Stroke Tc88:

3.75 in x 3.968 in (95.25 mm x 100.6 mm)

Bore X Stroke Tc103:

3.875 in x 4.25 in (98.4 mm x 108 mm) - for common big bore kits.

Compression Ratio Tc88:

8.8:1 (stock)

Compression Ratio Tc103:

9.0:1 (typical for conversions)

Horsepower Tc88:

Approx. 60-65 HP (at crankshaft, stock)

Torque Tc88:

Approx. 70-75 lb-ft (at crankshaft, stock)

Fuel Delivery:

Electronic Sequential Port Fuel Injection (ESPFI)

Fuel Type:

Unleaded gasoline, minimum 91 octane (R+M)/2 recommended

Ignition:

Distributorless Electronic Ignition (with crank position sensor)

🔧 Transmission

Type:

5-Speed Cruise Drive

Gear Ratios:

1st: 3.15:1, 2nd: 2.11:1, 3rd: 1.60:1, 4th: 1.22:1, 5th: 1.00:1

Primary Drive:

Multi-plate wet clutch, chain drive

Final Drive:

Belt drive

Optional Features:

Not typically applicable for this model year in terms of transmission type.

Fluid Type:

Harley-Davidson Formula + Transmission and Primary Chaincase Lubricant (or equivalent)

Fluid Capacity Primary:

Approx. 3 quarts (2.8 L)

Fluid Capacity Transmission:

Approx. 1 quart (0.95 L)

📐 Dimensions

Wheelbase:

Approx. 63.5 inches (1613 mm)

Length:

Approx. 93.4 inches (2372 mm)

Width:

Approx. 37.5 inches (952.5 mm)

Height:

Approx. 56.2 inches (1427.5 mm)

Dry Weight:

Approx. 700-750 lbs (318-340 kg), varies by model variant

Gross Vehicle Weight Rating Gvwr:

Approx. 1260 lbs (571.5 kg)

Saddlebag Capacity:

Integrated hard saddlebags, capacity varies

Tour Pak Capacity:

Optional, integrated hard case, capacity varies

🛡️ Safety Features

Crash Test Ratings:

Motorcycle safety is not rated by standard automotive crash test agencies like NHTSA or IIHS. Focus is on rider protection through design and equipment.

Brakes:

Dual 32 mm, 4-piston calipers on front, single 32 mm, 4-piston caliper on rear. Optional Anti-lock Braking System (ABS).

Suspension:

Adjustable front forks and rear shocks for optimal handling and stability.

Lighting:

Halogen headlamp, integrated turn signals, tail/brake lights.

Security:

Factory-installed H-D Smart Security System (optional or standard depending on trim).

💡 Technology Features

Audio System:

Often equipped with a CB radio, passenger intercom, and AM/FM radio with CD player, depending on trim level (e.g., Ultra Classic).

ABS:

Anti-lock Braking System (ABS) was an available option for 2004 FLH models.

Diagnostics:

OBD-II compliant diagnostic port for engine management and fault code retrieval.

🔧 Maintenance

Initial Service:

First service typically at 1,000 miles (1600 km) - includes oil change, filter, and comprehensive inspection.

Subsequent Oil Change:

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

Transmission Oil Change:

Every 10,000 miles (16,000 km) or annually.

Primary Chaincase Oil Change:

Every 5,000 miles (8,000 km) or annually.

Spark Plug Replacement:

Every 10,000 miles (16,000 km)

Air Filter Cleaning:

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

Engine Oil:

Harley-Davidson 20W-50 Genuine Motor Oil (or equivalent API SG or higher)

Transmission Oil:

Harley-Davidson Formula + Transmission & Primary Chaincase Lubricant (or equivalent)

Primary Chaincase Oil:

Harley-Davidson Formula + Transmission & Primary Chaincase Lubricant (or equivalent)

Brake Fluid:

DOT 4 (refer to manual for specific recommendations, especially if ABS equipped)

Cam Chain Tensioner:

Early Twin Cam models (pre-2007) used plastic cam chain tensioners which could wear prematurely and cause noise or damage. Manual will detail inspection and replacement procedures, often recommending upgraded hydraulic tensioners.

Crankshaft Runout:

Potential for excessive crankshaft runout, especially in modified engines. Manual will provide specifications for checking.

Oil Leaks:

Common areas for leaks include primary cover, transmission seal, and rocker box gaskets. Manual provides detailed procedures for gasket replacement and torque specifications.

📚 Vehicle History

Brand History:

Harley-Davidson, founded in 1903, is an iconic American motorcycle manufacturer with a long history of producing V-twin engine motorcycles.

Model Lineage:

The FLH series represents Harley-Davidson's flagship touring motorcycles, evolving from earlier models like the Panhead and Shovelhead. The Twin Cam engine platform replaced the Evolution engine in touring models starting in 1999.

Twin Cam Introduction:

The Twin Cam 88 was introduced in 1999, offering increased displacement and a more robust design compared to the Evolution Big Twin.

Manufacturing Location:

United States (primarily York, Pennsylvania and Milwaukee, Wisconsin)

🏆 Awards & Recognition

Brand Awards:

Harley-Davidson is a recipient of numerous industry awards and recognitions for its heritage, design, and performance.

Owner Satisfaction:

Consistently high owner satisfaction ratings for its touring motorcycles, valued for comfort, style, and community.

Manufacturing Standards:

Adheres to internal quality control and manufacturing standards, often exceeding regulatory requirements.