Segment:
Cruiser Motorcycle
Target Audience:
Harley-Davidson FXS Shovelhead owners, mechanics, restoration specialists
Comparable Models Era:
Other American V-Twins (e.g., some Indian models if still active), British twins (e.g., Triumph Bonneville)
Engine Type:
Iconic Shovelhead V-Twin engine
Design Philosophy:
Classic American V-twin styling with a focus on torque and rider experience.
Manual Value Proposition:
Essential for maintaining, troubleshooting, and repairing the 1981 FXS Shovelhead.
Engine:
Shovelhead OHV V-Twin Engine
Transmission:
4-Speed Cruise Drive Transmission
Electrical System:
Ignition, Lighting, Charging, Starting Systems
Fuel System:
Carburetion (e.g., Keihin butterfly, Linkert if applicable for 1981 variations), Fuel Tanks, Fuel Lines
Brakes:
Hydraulic Front Disc Brakes, Rear Drum Brakes (typical for FXS of this era)
Suspension:
Front Fork (likely FLT style telescopic), Rear Swingarm with Shock Absorbers
Frame And Bodywork:
Frame, Fenders, Fuel Tank, Seat, Handlebars, Controls
Wheels And Tires:
Spoked Wheels, Tire Sizes, Wheel Bearings
Exhaust System:
Exhaust Pipes, Mufflers
Clutch:
Clutch Assembly and Operation
Maintenance:
Oil Changes, Filter Replacements, Spark Plug Service, Lubrication Points
Troubleshooting:
Diagnostic Charts, Symptom-Based Problem Solving
Repair:
Engine Overhaul, Transmission Rebuild, Brake Caliper Service, Electrical Component Replacement
Adjustment:
Carburetor Tuning, Clutch Adjustment, Brake Adjustment, Primary Chain Adjustment
Disassembly And Assembly:
Component-Level Procedures for all major systems
Wiring Diagrams:
Complete Electrical Schematics
Depth:
Comprehensive Factory-Level Repair and Diagnostics
Detail Level:
Includes specifications, tolerances, torque values, and procedures for complete rebuilds.
Engine Family:
Shovelhead
Engine Configuration:
Air-cooled, 45-degree V-twin
Displacement:
73.7 cubic inches (1200cc) - Standard for FXS in 1981
Bore X Stroke:
3.4375 in. x 4.25 in. (87.3 mm x 108.0 mm)
Compression Ratio:
8.0:1 (Typical for 1981 Shovelhead models)
Horsepower:
Approx. 60-65 HP (Estimated - actual figures vary)
Torque:
Approx. 68-72 lb-ft @ 3200 RPM (Estimated)
Carburetor Type:
Keihin butterfly carburetor (e.g., KEI 36mm)
Fuel Requirement:
Unleaded gasoline, 87-octane minimum (RON+MON)/2
Fuel Tank Capacity:
Approx. 3.5 gallons (13.2 liters) for FXS
Crash Test Results:
N/A (Motorcycles are not subjected to standard automotive crash testing)
Brakes:
Single front disc brake, rear drum brake (effectiveness dependent on maintenance)
Lighting:
Headlight, Taillight, Turn Signals, Brake Light
Frame Integrity:
Steel frame construction
Oil Change Interval:
Typically every 2,500 - 3,000 miles (refer to manual for exact specification).
Primary Chain Tension Check:
Every 1,000 - 1,500 miles (crucial for Shovelheads).
Spark Plug Replacement:
Every 5,000 - 10,000 miles (dependent on plug type).
Engine Oil Type:
Viscosity recommendations vary, typically 20W-50 or 25W-50 motorcycle-specific oil. Refer to manual for specific Harley-Davidson recommendations or aftermarket equivalents approved for Shovelheads.
Engine Oil Capacity:
Approx. 3 quarts (2.8 liters) with filter change (refer to manual).
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid for hydraulic front brake (check manual).
Transmission Fluid Type:
Harley-Davidson 4-speed transmission oil or equivalent API GL-4 rated gear oil (as noted in transmission section).
Primary Chain Tensioner:
Wear on the primary chain tensioner is a common Shovelhead issue, leading to chain slap and potential damage. Manual will cover inspection and replacement.
Oil Leaks:
Shovelheads are known for minor oil leaks from various seals and gaskets due to age and design. Manual will guide on identifying and addressing these.
Carburetor Tuning:
Carburetors (especially older models) require periodic tuning and cleaning for optimal performance and starting.
Electrical Connections:
Corrosion or looseness in electrical connections can cause intermittent issues. The manual's wiring diagrams are crucial for diagnosis.
Heritage Description:
Iconic American motorcycle manufacturer with a long history of V-twin engines and cruiser designs.
Predecessor:
Evolved from earlier Big Twin models, integrating elements like the Shovelhead engine which replaced the Panhead.
Fxs Specifics:
The FXS model (often referred to as the 'Low Rider') was a custom cruiser variant of Harley-Davidson's Big Twin platform, known for its extended front end and lower seat height.
Shovelhead Era:
The Shovelhead engine was produced from 1966 to 1984, marking a significant era for Harley-Davidson.
Production Years Model:
The FXS was produced for several years within the Shovelhead era, with the 1981 model being a specific iteration.
Manufacturing Location:
Milwaukee, Wisconsin, USA
