🏷️ Basic Information

Make:

Harley-Davidson

Model:

FXS

Year:

1978

Engine Code Family:

Shovelhead

👋 Introduction

Positioning:

Essential resource for owners and technicians working on the iconic Harley-Davidson FXS Shovelhead model from 1978, known for its distinctive styling and robust performance.

Analysis:

This manual provides detailed, manufacturer-specific information, surpassing generic repair guides in accuracy and completeness for the FXS Shovelhead.

Features:

Focuses on the specific mechanical and electrical systems of the 1978 FXS Shovelhead, offering step-by-step procedures and critical torque specifications.

📋 Manual Details

Engine:

Complete overhaul, diagnosis, tuning, carburetion, ignition, lubrication

Transmission:

Disassembly, assembly, adjustment, lubrication, troubleshooting

Chassis:

Frame, forks, swingarm, suspension, wheels, brakes

Electrical:

Wiring diagrams, lighting, ignition system, charging system, starter

Bodywork And Trim:

Fenders, fuel tank, seat, handlebars, controls

Frame And Suspension:

Inspection and maintenance of frame components, steering head bearings, front fork assembly (including oil changes and seal replacement), and rear shock absorbers.

Estimated Pages:

300+

Type:

Service and Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Primary Systems:

Engine, Fuel, Ignition, Lubrication, Transmission, Clutch, Brakes, Suspension, Electrical System, Frame, Bodywork

Maintenance:

Oil changes, filter replacements, chain adjustment, brake adjustments, tune-ups

Repair:

Engine rebuild, transmission overhaul, carburetor repair, brake system service, electrical diagnostics, suspension component replacement

Troubleshooting:

Diagnostic charts, common problems and solutions, performance issues

Electrical System Repair:

Detailed wiring diagrams, troubleshooting steps for common electrical faults, charging system checks, and starter motor service.

Depth:

Comprehensive from basic maintenance to complete engine and transmission overhauls, including detailed electrical troubleshooting and wiring diagrams.

Diagnostic Procedures:

Detailed diagnostic charts and procedures for identifying and resolving engine, electrical, and drivetrain issues.

📊 Manual Specifications

File Type:

PDF (Portable Document Format)

Quality:

High-resolution scans suitable for printing, clear text and diagrams.

Binding:

N/A (Digital Format)

Paper:

N/A (Digital Format)

Completeness:

Complete service and repair manual covering all aspects of maintenance, troubleshooting, and repair for the 1978 FXS Shovelhead.

⚙️ Engine Specifications

Engine Type:

Air-cooled, 45-degree V-twin

Engine Family:

Shovelhead

Displacement:

74 cubic inches (1215cc)

Bore X Stroke:

3.4375 in. x 4.25 in. (87.31 mm x 107.95 mm)

Compression Ratio:

8.0:1 (Typical)

Valve Train:

Overhead valves, pushrod-actuated

Horsepower Estimate:

Approximately 60-65 HP @ 5500 RPM

Torque Estimate:

Approximately 70-75 ft-lbs @ 3500 RPM

Carburetor:

Keihin Butterfly (often CV) or Linkert (earlier models), specific to FXS configuration. Manual will detail tuning and rebuild.

Fuel Type:

Unleaded gasoline (91 octane or higher recommended)

Oil Type:

Harley-Davidson High Performance 20W50 or equivalent V-twin specific oil

Oil Capacity:

Approximately 3 quarts (2.8 liters) for crankcase and oil tank combined.

Ignition Type:

Contact point ignition (points and condenser) or early electronic ignition (e.g., Fairbanks Morse or aftermarket). Manual details setup and timing.

Carburetor Tuning:

Comprehensive instructions for adjusting fuel mixture, idle speed, and float levels for optimal performance and emissions compliance for the era.

🔧 Transmission

Type:

4-speed constant mesh, foot-shifted

Clutch:

Wet, multi-plate, cable-operated

Primary Drive:

Duplex chain

Final Drive:

Belt drive

Transmission Fluid:

Harley-Davidson Formula+ Transmission Oil or a high-quality 75W-90 GL-1 gear oil

Gear Ratios:

Specific gear ratios for each of the 4 speeds are detailed in the manual for inspection and troubleshooting.

📐 Dimensions

Wheelbase:

Approximately 62 inches (1575 mm)

Length:

Approximately 90 inches (2286 mm)

Dry Weight:

Approximately 575 lbs (261 kg)

🛡️ Safety Features

Ratings:

N/A (Motorcycle safety ratings are not directly comparable to automobiles and were not standardized as they are today).

Braking System:

Front: Disc brake; Rear: Drum brake. Manual covers inspection, pad replacement, fluid flush.

Lighting:

Headlight, tail light, brake light, turn signals. Manual includes troubleshooting for electrical circuits.

💡 Technology Features

Infotainment System:

N/A (This era of motorcycle did not feature electronic infotainment systems. Focus is on mechanical and electrical fundamentals).

🔧 Maintenance

Oil Change Interval:

Every 2,000-3,000 miles or annually, whichever comes first. Manual details procedure for engine oil and oil filter.

Transmission Service:

Inspect and top-up transmission fluid at regular intervals. Full flush and refill recommended every 10,000-15,000 miles. Manual details procedure and fluid type.

Chain Adjustment:

Check and adjust final drive belt tension every 2,000-3,000 miles. Manual provides specifications for belt tension.

Spark Plug Replacement:

Recommended replacement every 5,000-10,000 miles or as needed based on inspection. Manual provides correct spark plug type and gap.

Engine Oil Type:

Harley-Davidson High Performance 20W50 Motorcycle Oil (or equivalent API SG rated oil).

Transmission Fluid Type:

Harley-Davidson Formula+ Transmission Oil (or equivalent 75W-90 GL-1 gear oil).

Primary Chain Case Oil:

Harley-Davidson Primary Chaincase Lubricant (or equivalent Type 'F' ATF for specific applications, check manual).

Brake Fluid Type:

DOT 4 or DOT 5 silicone fluid (depending on original specification, verify with manual or existing system).

Common Problems:

Oil leaks (especially from generator or primary), valve adjustments, primary chain adjustment, carburetor tuning, ignition system maintenance. Manual addresses these with diagnostic and repair procedures.

📚 Vehicle History

Heritage:

Harley-Davidson, founded in 1903, has a rich history of American motorcycle manufacturing, evolving from small, utilitarian bikes to iconic V-twins.

Fxs Evolution:

The FXS originated from the FX Super Glide line, introduced in 1971, featuring a blend of Sportster and Electra Glide components. The FXS (Low Rider) model specifically debuted in 1977, characterized by its lower seat height, pullback handlebars, and extended front end, offering a more relaxed riding position.

Production Era:

The Shovelhead engine was produced from 1966 to 1984. The FXS Low Rider model was a significant variant within this era.

🏆 Awards & Recognition

Model Recognition:

The Shovelhead engine and its derivatives are considered a legendary powerplant in motorcycle history, celebrated for their distinctive sound and character. The FXS Low Rider model is recognized for popularizing the cruiser segment within Harley-Davidson's lineup.