Target Audience:
Harley-Davidson FLT series owners and independent repair shops seeking comprehensive repair and maintenance information for their Twin Cam era motorcycles.
Value Proposition:
Provides official-level technical detail and procedures comparable to dealer service manuals, enabling significant cost savings on maintenance and repairs.
Detail Level:
Extensive detail, precise torque specifications, exploded views, wiring diagrams, and troubleshooting charts.
Utility:
Essential for any owner or technician performing anything beyond basic upkeep.
Engine:
Engine disassembly, assembly, lubrication, cooling system (air-cooled), fuel delivery (carburetor and early EFI), ignition, exhaust, internal components (pistons, cylinders, crankshaft, camshafts, valvetrain).
Transmission:
5-speed Cruise Drive transmission (disassembly, assembly, clutch operation, gear shifting mechanisms, lubrication).
Drivetrain:
Primary drive (clutch, compensator sprocket), final drive (belt drive system, tensioner, wheel hub).
Electrical System:
Battery, charging system (stator, regulator/rectifier), ignition system, lighting (headlight, taillight, signals), starter system, instrument cluster, wiring diagrams, diagnostic codes.
Brakes:
Front and rear brake systems, hydraulic lines, master cylinders, calipers, brake pads, rotors, bleeding procedures.
Suspension:
Front fork (telescopic, air-assisted), rear shock absorbers, linkage (if applicable), adjustment and servicing.
Chassis And Frame:
Frame components, steering head bearings, swingarm, wheel bearings, stands.
Bodywork And Trim:
Fairings, saddlebags, mounting hardware, fuel tank, fenders, seat, controls, fairing lowers.
Fuel System:
Carburetor (Keihin CV, specific models) or early EFI systems, fuel pump, fuel lines, fuel tank servicing.
Maintenance:
Routine inspections, oil changes, filter replacements (oil, air), spark plug service, brake fluid flushes, battery maintenance, tire pressure checks, lubrication points.
Troubleshooting:
Diagnostic procedures for common starting, running, and electrical issues. Symptom-based troubleshooting guides.
Repair:
Detailed step-by-step instructions for component removal, repair, and reinstallation for all major systems.
Diagnostics:
Diagnostic trouble codes (DTCs) interpretation, electrical circuit testing, sensor testing, fuel system diagnostics.
Depth:
Expert level, covering complete engine rebuilds, transmission overhauls, electrical system diagnostics, and advanced troubleshooting. Suitable for professional mechanics and experienced DIY enthusiasts.
Engine Family:
Harley-Davidson Twin Cam 88
Displacement:
88 cubic inches (1450cc)
Configuration:
Air-cooled, 45-degree V-twin
Bore X Stroke:
3.75 in x 4.00 in (95.25 mm x 101.6 mm)
Compression Ratio:
Typically 8.8:1 or 9.1:1 depending on exact model/year
Valvetrain:
Overhead valve (OHV), 2 valves per cylinder, pushrod actuated.
Horsepower Est:
Approx. 65-75 HP (varies by year and specific model)
Torque Est:
Approx. 75-85 lb-ft (varies by year and specific model)
Twin Cam 103:
103 cubic inches (1690cc), typically achieved through larger bore cylinders or aftermarket kits for this period. Performance figures will be higher.
Peak Horsepower Rpm:
Around 5200 RPM
Peak Torque Rpm:
Around 3500 RPM
Carburetor Model:
Keihin CV (Constant Velocity) carburetor, typically 40mm.
Efi System:
Early Electronic Fuel Injection (EFI) systems may be covered for later years in this range.
Type:
5-speed Manual, Cruise Drive
Availability:
N/A (5-speed was standard for this era FLT)
Gear Ratios:
Specific gear ratios will be detailed in the manual, typically optimized for cruising.
Clutch Type:
Wet, multi-plate, diaphragm spring
Transmission Fluid:
Harley-Davidson Formula + Transmission, Lubricant & Primary Chain Case Oil (or equivalent API GL-4 specification SAE 75W-90 synthetic gear oil).
Wheelbase:
Approx. 63.5 inches (1613 mm)
Length:
Approx. 93.4 inches (2372 mm)
Seat Height:
Approx. 27.1 inches (688 mm) (unladen)
Dry Weight:
Approx. 700-750 lbs (318-340 kg) (varies by model)
Gross Vehicle Weight Rating:
Typically 1200 lbs (544 kg) or more.
Saddlebag Capacity:
Significant, designed for touring, with hard-shell construction. Specific volume in cubic feet will be in manual.
Crash Test Data:
Motorcycles typically do not have standardized crash test ratings like automobiles. Focus is on rider protection features.
Braking System:
Dual front disc brakes, single rear disc brake with hydraulic actuation. ABS (Anti-lock Braking System) became available on some models in this range.
Lighting:
Halogen headlight, integrated turn signals, brake lights, running lights for visibility.
Frame Construction:
Robust steel frame designed for stability and load-carrying.
Rider Controls:
Ergonomic handlebar and seating position designed for rider comfort and control on long journeys.
First Service:
Typically at 1,000 miles (1,600 km) - includes engine oil and filter change, primary chain case oil check, clutch adjustment, and general inspection.
Subsequent Oil Changes:
Every 5,000 miles (8,000 km) or annually, whichever comes first.
Air Filter Service:
Inspect every 5,000 miles (8,000 km), replace as needed or based on operating conditions.
Spark Plug Replacement:
Typically at 10,000-15,000 miles (16,000-24,000 km) or as per manual recommendation.
Brake Fluid Flush:
Every 2 years or 24,000 miles (38,000 km), whichever comes first.
Engine Oil:
Harley-Davidson SYN3 (Fully Synthetic) SAE 20W-50 or equivalent V-twin specific motorcycle oil meeting Harley-Davidson specifications (e.g., H-D 360, SAE 20W-50).
Engine Oil Capacity:
Approx. 4 quarts (3.8 liters) with filter change.
Primary Chain Case Oil:
Harley-Davidson Formula + Transmission, Lubricant & Primary Chain Case Oil or equivalent.
Primary Chain Case Oil Capacity:
Approx. 1 quart (0.95 liters)
Brake Fluid:
DOT 4 Brake Fluid (non-silicone based).
Cam Chain Tensioners:
Early Twin Cam 88 models used plastic cam chain tensioner shoes which could wear prematurely, leading to potential engine damage. Upgraded hydraulic tensioners are recommended for affected models.
Crankshaft Runout:
Some early Twin Cam engines experienced excessive crankshaft runout, potentially leading to vibration and component wear. Measurement and diagnosis are detailed in the manual.
Primary Drive Assembly:
Issues related to compensator sprocket wear or primary bearing failures can occur; proper maintenance and inspection are crucial.
Harley Davidson Legacy:
Harley-Davidson has a long history dating back to 1903, renowned for its iconic V-twin engines, cruiser styling, and touring capabilities.
Flt Series:
The FLT designation represents Harley-Davidson's touring platform, evolving from earlier models to incorporate features like the fairing, saddlebags, and improved chassis and engine technology. The introduction of the Twin Cam engine in 1999 marked a significant technological advancement.
Twin Cam Engine Introduction:
The Twin Cam 88 engine, launched in 1999, replaced the Evolution (Evo) engine, offering increased displacement, improved torque, and a more modern design with dual spark plugs per cylinder for better combustion.
Manufacturing Location:
Primarily manufactured in the United States (e.g., York, Pennsylvania and Milwaukee, Wisconsin).
