Segment:
Cruiser Motorcycle
Target Audience:
Harley-Davidson Dyna owners, independent repair shops, motorcycle enthusiasts
Competitors:
Other American V-twin motorcycles, Japanese cruisers
Platform:
Dyna chassis, known for its blend of classic styling and modern performance.
Versatility:
The Dyna platform served as a base for various sub-models (e.g., Super Glide, Low Rider, Fat Bob, Street Bob) with minor variations covered within the scope of this manual.
Engine:
V-Twin Twin Cam 88, Twin Cam 88B (carbureted and fuel-injected variants as applicable to the 2004 Dyna line)
Transmission:
5-speed Cruise Drive, clutch assembly, primary drive system
Fuel System:
Carburetor (Keihin CV) and Electronic Fuel Injection (EFI) systems, fuel pump, fuel tank, fuel lines
Ignition System:
Electronic ignition module, ignition coil, spark plugs, wiring
Electrical System:
Battery, charging system (stator, regulator/rectifier), starter motor, lighting (headlight, taillight, turn signals, brake light), horn, switches, fuses, relays, wiring diagrams
Chassis And Suspension:
Frame, front forks (telescopic), rear shock absorbers, swingarm, wheel bearings, steering head bearings
Brakes:
Front and rear disc brakes, brake calipers, master cylinders, brake lines, brake fluid specifications
Wheels And Tires:
Wheel types, tire specifications, tire pressure recommendations, wheel balancing
Bodywork And Trim:
Fenders, fuel tank, seat, handlebars, controls, instrumentation, body panels
Exhaust System:
Exhaust pipes, mufflers, mounting hardware
Diagnostics And Troubleshooting:
Diagnostic trouble codes (DTCs) for EFI models, symptom-based troubleshooting guides, common issues and their resolutions
Cooling System:
Air-cooled system components.
Maintenance:
Routine inspections, lubrication, fluid changes, filter replacements, spark plug replacement, belt tensioning
Repair:
Engine disassembly and reassembly, transmission overhaul, brake system repairs, electrical component replacement, suspension component servicing
Installation:
Component installation and removal procedures for major systems
Adjustment:
Carburetor adjustment, clutch adjustment, throttle cable adjustment, brake lever adjustment
Troubleshooting Engine:
Detailed steps for diagnosing engine performance issues, starting problems, and abnormal noises.
Troubleshooting Electrical:
Circuit-specific troubleshooting guides based on wiring diagrams and common electrical faults.
Depth:
Comprehensive: Covers basic maintenance to complete engine and transmission rebuilds, including detailed diagnostic procedures and wiring diagrams.
Searchable:
Yes (typically, depending on PDF origin)
Compatibility:
Compatible with standard PDF readers on computers, tablets, and smartphones.
Quality:
High resolution, suitable for printing all pages or selected sections
Binding:
N/A (Digital Download PDF)
Paper:
N/A (Digital Download PDF)
Engine Family:
Harley-Davidson Twin Cam
Engine Type:
Air-cooled, 45-degree V-twin
Displacement:
1449 cc (88 cubic inches)
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 (est. at crank, varies by specific model/tuning)
Torque:
Approx. 75-80 lb-ft (est. at crank, varies by specific model/tuning)
Carburetor Model:
Keihin CV (Constant Velocity) 40mm (for carbureted models)
Fuel Injection System:
Electronic Sequential Port Fuel Injection (ESPFI) (for EFI models)
Oil Type:
Harley-Davidson Genuine V-Twin Oil, SAE 20W50
Oil Capacity:
3.0 US qt (2.8 L) (with filter change)
Transmission Type:
5-speed Constant Mesh
Gear Ratios:
1st: 10.106, 2nd: 6.857, 3rd: 4.978, 4th: 3.874, 5th: 3.150 (Typical, consult manual for exact ratios)
Primary Drive:
Duplex chain, 34/46 ratio
Final Drive:
Belt drive, 32/66 ratio
Transmission Oil Type:
Harley-Davidson Synthetic Transmission Fluid, SAE 75W90
Transmission Oil Capacity:
0.9 US qt (0.85 L)
Instrumentation:
Analog speedometer, tachometer (on some models), fuel gauge, indicator lights, odometer, trip meter.
ABS:
Anti-lock Braking System (ABS) was an optional feature for some 2004 Dyna models, not standard across the board. Consult specific model VIN for confirmation.
Diagnostic Ports:
Diagnostic connector for EFI models, allowing for connection to Harley-Davidson diagnostic tools or compatible aftermarket scanners for fault code retrieval and data monitoring.
First Service:
1,000 miles (1,600 km) or 6 months (whichever comes first), includes oil change, filter replacement, and comprehensive inspection.
Subsequent Oil Changes:
Every 5,000 miles (8,000 km) or 12 months, whichever comes first.
Belt Inspection Tensioning:
Inspect every 5,000 miles (8,000 km), adjust tension as needed per manual specifications.
Spark Plug Replacement:
Recommended at 10,000-15,000 miles (16,000-24,000 km) or as needed based on inspection.
Engine Oil Spec:
SAE 20W50 Harley-Davidson Genuine V-Twin Oil or equivalent high-quality motorcycle oil meeting API CI-4 or higher.
Transmission Oil Spec:
SAE 75W90 Harley-Davidson Synthetic Transmission Fluid or equivalent GL-5 rated gear oil.
Primary Chain Case Oil Spec:
Harley-Davidson Primary Chain Lubricant or SAE 20W50 motor oil.
Brake Fluid Spec:
DOT 4 (refer to manual for specific formulation, typically non-silicone based).
Common Issues:
Stalling due to carburetor issues (CV carb), aging wiring harness connectors, potential for oil leaks from rocker boxes or base gaskets, clutch cable adjustment sensitivity.
Vibration Dampening:
Dyna models utilize frame-mounted engines, leading to more engine vibration transmitted to the rider compared to rubber-mounted Softail models. This is characteristic, not necessarily a fault.
Brand History:
Harley-Davidson, founded in 1903, is an iconic American motorcycle manufacturer with a rich history in performance and customization.
Dyna Lineage:
The Dyna platform was introduced in 1991, evolving from the earlier Shovelhead and Evolution engine motorcycles. The 2004 model year represents a mature iteration of this popular platform.
Production Period:
Dyna models were produced from 1991 until the platform was discontinued in 2017, replaced by the Softail platform.
Manufacturing Location:
Harley-Davidson motorcycles, including the Dyna models, are primarily manufactured in the United States.
