Target Audience:
Owners and technicians specializing in vintage Harley-Davidson motorcycles, particularly those who value authenticity and hands-on maintenance of the Shovelhead era.
Value Proposition:
Provides factory-accurate information, essential for preserving the integrity and functionality of a classic 1981 Harley-Davidson FL, offering a higher level of detail than generic repair guides.
Feature 1:
Directly from Harley-Davidson factory documentation, ensuring accuracy and completeness.
Feature 2:
Comprehensive coverage of the iconic 1340cc Shovelhead engine.
Feature 3:
Detailed, step-by-step instructions with clear procedural sequences.
Engine:
Full disassembly, assembly, inspection, and repair of the 1340cc Shovelhead engine, including cylinders, pistons, crankshaft, camshaft, valves, oil pump, and ignition system.
Transmission:
Service, repair, and overhaul of the 4-speed constant mesh transmission (often referred to as the '4-speed'). Includes clutch, primary drive, and gearbox components.
Fuel System:
Carburetor (e.g., Keihin butterfly or Bendix) specifications, tuning, rebuilding, and troubleshooting. Fuel tank and lines maintenance.
Electrical System:
Wiring diagrams, ignition system troubleshooting, charging system (generator/alternator, regulator), lighting, starting system, and battery service.
Brakes:
Front and rear brake system inspection, repair, and fluid service. Includes master cylinders, calipers, brake lines, and parking brake systems if applicable.
Suspension:
Front fork (telescopic) and rear swingarm suspension service, including oil changes, seal replacement, and component inspection.
Frame And Body:
Frame inspection, mounting points, fenders, fuel tank, seat, and other body components. Includes removal and installation procedures.
Routine Maintenance:
Oil changes, filter replacements, spark plug service, air filter cleaning/replacement, chain adjustment (if applicable), brake adjustments.
Troubleshooting:
Systematic diagnostic procedures for common performance issues, starting problems, electrical faults, and mechanical failures.
Disassembly Assembly:
Step-by-step instructions for removing, dismantling, inspecting, and reassembling all major motorcycle components.
Repair Rebuild:
Detailed instructions for rebuilding the engine, transmission, carburetor, brake systems, and other key assemblies.
Special Tools:
Identification and usage of specialized tools required for specific service and repair procedures.
Depth:
Comprehensive, covering from basic adjustments and maintenance to full engine and transmission overhauls. Designed for both DIY enthusiasts and professional mechanics.
Digital Quality:
N/A (Print Manual)
Print Type:
Professionally printed, likely on durable paper stock suitable for workshop environments.
Binding:
Likely perfect bound or saddle-stitched, designed for lay-flat use on a workbench.
Paper Quality:
Durable, possibly semi-gloss paper designed to resist grease and dirt in a workshop setting.
Engine Type:
Air-cooled, V-twin, four-stroke OHV (Overhead Valve)
Engine Code Variant:
Shovelhead
Bore X Stroke:
Approximately 3.4375 in x 4.25 in (87.3 mm x 108 mm)
Compression Ratio:
Typically around 7.0:1 to 8.0:1 depending on variant.
Horsepower:
Estimated 55-65 HP (at crank), depending on tuning and specific model variant.
Torque:
Estimated 75-85 ft-lbs (at crank).
Carburetor:
Typically Keihin butterfly (e.g., CV) or Bendix/Zenith (less common by 1981 for FL models, but possible).
Fuel Type:
Unleaded gasoline, octane rating typically 87-89.
Ignition Type:
Contact breaker points or early electronic ignition (e.g., points replacement kits) with dual-fire coil.
Oil Capacity:
Approximately 3 quarts (2.8 liters) with filter change.
Oil Type Specification:
Viscosity: SAE 20W-50 or SAE 25W-50, typically Harley-Davidson-approved motorcycle oil or equivalent with API SF or SG classification. Avoid oils with excessive friction modifiers.
Transmission Type:
4-speed constant mesh, floorboard shift (typically left-side shift).
Transmission Options:
None offered by factory for this specific model year and configuration.
Primary Drive:
Primary chain drive within a sealed primary cover, often with a wet clutch.
Transmission Fluid:
SAE 80W-90 API GL-4 gear oil for the transmission and primary case.
Wheelbase:
Approximately 62.5 inches (1588 mm)
Overall Length:
Approximately 90 inches (2286 mm)
Dry Weight:
Approximately 600-650 lbs (272-295 kg) depending on specific FL model variant (e.g., Electra-Glide, Super Glide).
Gross Vehicle Weight Rating:
Typically around 1000 lbs (454 kg).
Safety Standards:
Manufactured to meet applicable U.S. Federal Motor Vehicle Safety Standards (FMVSS) for motorcycles of that era. No formal crash test ratings as commonly understood today.
Braking:
Dual-disc front brake (often), single-disc rear brake. Mechanical parking brake on some models.
Lighting:
Headlight, taillight, brake light, turn signals, and reflectors.
Engine Oil Change:
Every 2,000-3,000 miles (3,200-4,800 km) or annually, whichever comes first. Check manual for exact factory recommendation.
Transmission Oil Change:
Every 5,000-6,000 miles (8,000-9,600 km) or annually.
Primary Chain Tension:
Check and adjust as needed, typically every 5,000 miles (8,000 km).
Spark Plugs:
Inspect every 5,000 miles (8,000 km), replace as needed. Typical plugs: Champion H8R, H10R, or equivalent NGK/Denso.
Brake Fluid:
Inspect for contamination annually, replace as needed. DOT 4 or DOT 5 is often debated for older HDs, consult manual for specific fluid type used by H-D in '81.
Engine Oil Viscosity:
SAE 20W-50 or SAE 25W-50.
Transmission Gear Oil:
SAE 80W-90 API GL-4.
Fork Oil Viscosity:
Typically SAE 10W or SAE 20W fork oil, depending on specific fork type and preference.
Shifter Pawl Spring:
Weak or broken shifter pawl spring leading to missed shifts or inability to engage gears.
Primary Chain Stretching:
Stretching of the primary chain requiring frequent adjustment or replacement.
Oil Leaks:
Common oil leaks from various seals and gaskets, especially around the engine and transmission.
Carburetor Tuning:
Carburetors of this era often require meticulous tuning for optimal performance.
Electrical Gremlins:
Aging wiring and connectors can lead to intermittent electrical issues.
Brand Legacy:
Harley-Davidson, established 1903, known for its iconic V-twin engines and cruiser motorcycles.
Model Lineage:
The FL designation represents Harley-Davidson's large-displacement, big-twin touring and cruiser motorcycles. The 1340cc engine (often called the 'Shovelhead' due to its rocker box design) was a significant evolution from the Panhead and Knucklehead eras, in production from 1966 to 1984.
Production Period:
1981 marked the continued production of the Shovelhead engine within the FL platform, just prior to the introduction of the Evolution engine ('Evo') in 1984.
Historical Significance:
The Shovelhead engine, despite its known quirks, is a significant and sought-after engine in Harley-Davidson history, representing a transitional period before the Evo engine.
Reliability Perception:
While not known for the bulletproof reliability of later models, when properly maintained and repaired according to factory specifications, Shovelhead engines can be dependable. This manual is key to achieving that.
