🏷️ Basic Information

Make:

Harley-Davidson

Model:

FXS Low Rider

Years Covered:

1978, 1979, 1980

Engine Family Code:

Shovelhead

👋 Introduction

Historical Context:

The FXS Low Rider was a significant model in Harley-Davidson's lineup, offering a more custom and lower-slung profile compared to other big twins, appealing to riders seeking a cruiser aesthetic.

Key Competitors:

Rivals included other American V-twin motorcycles and increasingly, Japanese cruiser offerings.

Distinctive Attributes:

Characteristic 'Shovelhead' engine, distinctive styling, low seat height, often featuring cast wheels and a smaller fuel tank than other models.

📋 Manual Details

Primary Coverage:

Complete service, repair, and workshop procedures for the Harley-Davidson FXS Low Rider motorcycle.

Diagnostic Coverage:

Troubleshooting guides, fault diagnosis, and common issue resolution.

Maintenance Coverage:

Scheduled maintenance, routine checks, and preventative service recommendations.

Disassembly Reassembly:

Detailed step-by-step instructions for component removal, overhaul, and reinstallation.

Estimated Page Count:

Likely over 400 pages (typical for factory service manuals of this era).

Type:

Factory Service Manual / Workshop Manual

Language:

English

Format:

Downloadable PDF

File Type:

PDF

Searchability:

Likely text-searchable PDF for efficient information retrieval.

Quality:

High-resolution scans ensuring clarity of text and diagrams.

Binding For Digital:

N/A (Digital Download)

Paper For Digital:

N/A (Digital Download)

📖 Manual Coverage

Engine Mechanical:

Cylinder heads, cylinders, pistons, connecting rods, crankshaft, camshafts, valve train, timing.

Fuel System:

Carburetor (e.g., Keihin Butterfly), fuel tanks, fuel lines, fuel filters.

Ignition System:

Magneto ignition, ignition coils, spark plugs, ignition timing, electronic ignition components (if applicable for later production).

Electrical System:

Wiring diagrams, lighting, charging system (alternator/generator), battery, starter motor, switches.

Transmission Drivetrain:

Primary drive, clutch, 4-speed transmission (and its internal components), final drive belt/chain.

Suspension:

Front fork (e.g., 35mm or 38mm), rear shock absorbers, swingarm, linkage.

Braking System:

Front and rear brake systems (hydraulic disc or drum), brake lines, master cylinders, calipers.

Frame Chassis:

Frame inspections, steering head bearing maintenance, wheel alignment.

Bodywork Fittings:

Fenders, fuel tank, seat, handlebars, control levers, footpegs.

Preventative Maintenance:

Oil changes, filter replacements, spark plug checks, chain adjustment, lubrication points.

Engine Rebuild:

Complete engine disassembly, inspection, measurement, component replacement, and reassembly.

Carburetor Overhaul:

Disassembly, cleaning, jetting, adjustment, and rebuilding of the stock carburetor.

Transmission Repair:

Gearbox disassembly, inspection of gears, shafts, bearings, and shift drum.

Electrical Troubleshooting:

Diagnosis of common electrical faults using wiring diagrams and test procedures.

Suspension Service:

Fork oil changes, seal replacement, shock absorber service.

Brake System Maintenance:

Bleeding brakes, replacing brake pads/shoes, caliper servicing.

Wheel Bearing Replacement:

Service and replacement of wheel bearings.

Depth Level:

Comprehensive, covering all aspects from basic maintenance to full engine and transmission rebuilds, including detailed diagnostic procedures.

Diagnostic Tools:

Guidance on using basic hand tools and specialized Harley-Davidson diagnostic equipment relevant to the era.

Torque Specifications:

Detailed torque values for critical fasteners across all systems.

Clearances Tolerances:

Specific measurements for engine components, bearings, and other critical wear items.

⚙️ Engine Specifications

Engine Type:

Air-cooled, 45-degree V-twin, OHV (Overhead Valve)

Engine Displacement:

73.7 cubic inches (1207 cc) - commonly referred to as 74 cubic inches.

Bore X Stroke:

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

Compression Ratio:

Approximately 8.0:1 (stock)

Horsepower Rating:

Approximately 60-65 hp (at the crankshaft, estimated for stock tune)

Torque Rating:

Approximately 70-75 ft-lbs (at the crankshaft, estimated for stock tune)

Carburetor Type:

Typically a single Keihin Butterfly carburetor (e.g., CV or constant velocity type).

Fuel Octane Rating:

Recommended 91 octane unleaded gasoline.

Oil Type:

Harley-Davidson recommends specific V-twin motorcycle oils, typically SAE 20W-50 or SAE 50.

Oil Capacity:

Approximately 3 quarts (2.8 liters) with filter change.

🔧 Transmission

Transmission Type:

4-speed, constant mesh, foot-shifted

Optional Transmission:

N/A for this model year and variant.

Primary Drive:

Chain drive within a primary case.

Final Drive:

Belt drive (common for FXS models).

Clutch Type:

Wet multi-plate clutch, operated by cable.

Transmission Oil Type:

Harley-Davidson recommends specific transmission oil; check manual for exact specification (often a heavier weight oil or specialized gear lubricant).

📐 Dimensions

Wheelbase:

Approximately 62.5 inches (1588 mm)

Seat Height:

Approximately 26 inches (660 mm) (unladen)

Length:

Approximately 90 inches (2286 mm)

Dry Weight:

Approximately 500-520 lbs (227-236 kg)

Fuel Capacity:

Approximately 3.5 gallons (13.2 liters)

🛡️ Safety Features

Safety Ratings:

Motorcycles of this era did not undergo formal NHTSA safety ratings. Safety relies on rider skill and mechanical integrity.

Active Safety Features:

Hydraulic disc front brake, drum rear brake (or early disc depending on exact configuration).

Passive Safety Features:

Sturdy frame, reliable mechanical components, rider ergonomics for control.

💡 Technology Features

Infotainment System:

N/A for this era; basic analog gauges (speedometer, tachometer, oil pressure, neutral indicator).

🔧 Maintenance

Oil Change Interval:

Typically every 2,000-3,000 miles or annually, whichever comes first.

Primary Chain Tensioner Check:

Regular checks recommended, especially on models prone to wear.

Spark Plug Replacement:

Every 5,000-7,500 miles.

Brake Fluid Flush:

Every 1-2 years.

Engine Oil Grade:

SAE 20W-50 or SAE 50 motorcycle-specific oil.

Transmission Oil Grade:

Consult manual for specific Harley-Davidson recommended transmission fluid.

Primary Chain Case Oil:

Harley-Davidson primary chain case oil or equivalent (separate from engine oil).

Fork Oil Type:

Specific weight fork oil, e.g., Harley-Davidson Type 'E' or 'B' (check manual for exact recommendation for the FXS).

Oil Leaks:

Common across Shovelheads due to static seals and oil pump design. Manual will detail gasket replacement and sealing procedures.

Carburetor Tuning:

May require periodic adjustment or rebuilding due to wear or fuel quality changes. Manual provides tuning guidance.

Primary Chain Tensioner Wear:

The tensioner can wear, leading to noise and potential clutch slippage. Manual covers inspection and replacement.

Valve Guide Wear:

Can lead to oil consumption. Manual details valve guide inspection and replacement procedures.

Generator/Alternator Issues:

Electrical charging system can be prone to issues. Manual provides diagnosis for the charging system.

📚 Vehicle History

Harley Davidson Legacy:

Harley-Davidson has a long and storied history dating back to 1903, synonymous with American motorcycle culture and the V-twin engine.

Shovelhead Development:

The Shovelhead engine was an evolution of the Panhead, produced from the mid-1960s to 1984, known for its distinctive rocker box design and robust performance, though also for its oil leaks and vibration characteristic of the era.

Fxs Low Rider Introduction:

The FXS Low Rider debuted in 1977 as part of Harley-Davidson's effort to introduce more styling-conscious and rider-friendly models, aiming for a custom look and feel.

Manufacturing Location:

Milwaukee, Wisconsin, USA.

🏆 Awards & Recognition

Model Recognition:

The FXS Low Rider is recognized as a classic American motorcycle and a significant model in Harley-Davidson's history, contributing to the cruiser segment's evolution.

Consumer Ratings:

While formal ratings weren't standard, these bikes are highly regarded by enthusiasts for their character and classic V-twin appeal.

Manual Certifications:

Factory service manuals are official documentation and are considered the authoritative source for service and repair.