Target Audience:
Owners of 1985-1990 Harley-Davidson FLST/FXST Softail models seeking in-depth technical information for maintenance, repair, and restoration.
Value Proposition:
Provides official factory procedures and specifications, offering a higher level of accuracy and completeness compared to aftermarket manuals.
Manual Advantages:
Includes detailed diagrams, step-by-step instructions, torque specifications, and troubleshooting guides essential for proper servicing.
Engine Systems:
Engine teardown, assembly, lubrication, cooling, fuel and exhaust systems, ignition system, carburation (Keihin CV/Linkert depending on model year/spec).
Transmission Systems:
Clutch operation, primary drive, transmission assembly and disassembly, gear shifting mechanisms, final drive.
Chassis Systems:
Frame inspection and repair, suspension (front fork, rear shock absorbers), steering assembly, wheel bearings, brake systems (front and rear hydraulic discs), electrical system (wiring diagrams, charging system, lighting, ignition switch).
Bodywork And Trim:
Body panel removal and installation, fenders, fuel tank, seat, fairings (if applicable), controls, and accessories.
Maintenance Procedures:
Regular scheduled maintenance, oil and filter changes, spark plug replacement, chain adjustment, brake fluid flushes, battery maintenance.
Repair Procedures:
Complete engine rebuilds, transmission overhauls, carburetor tuning and repair, suspension component replacement, brake caliper and master cylinder service, electrical troubleshooting.
Troubleshooting:
Diagnostic procedures for common starting issues, running problems, electrical faults, and braking system malfunctions.
Special Tools:
Identification and usage of specialized Harley-Davidson tools required for specific repairs and adjustments.
Depth:
Comprehensive factory-level detail suitable for professional technicians and experienced DIY enthusiasts, including torque specifications, tolerances, and diagnostic flowcharts.
Digital Format Characteristics:
If PDF, expect searchable text, high-resolution diagrams, and printable pages. Often includes interactive links for navigation.
Printed Format Characteristics:
Typically printed on durable paper stock with clear, high-quality diagrams and photographs. Binding usually robust for workshop use.
Binding:
Likely perfect bound (paperback) or spiral bound for ease of use on a workbench.
Paper Stock:
Durable, possibly coated paper to resist grease and workshop contaminants.
Engine Type:
Evolution (Evo) V-Twin Pushrod OHV
Displacement:
82" cubic inches (1337cc) for most models in this period. Some variants might exist.
Bore X Stroke:
3.496 in x 4.250 in (88.8 mm x 108 mm)
Compression Ratio:
Approximately 8.3:1 to 9.0:1 depending on year and specific model.
Horsepower Estimate:
Around 55-65 HP (approximate, varies by tuning and year)
Torque Estimate:
Around 65-75 ft-lbs (approximate, varies by tuning and year)
Carburetor:
Typically Keihin CV (Constant Velocity) carburetor, or potentially Linkert on earlier models/specific configurations.
Fuel Type:
Unleaded Gasoline, 90+ octane recommended.
Engine Mounting:
Rubber isolated engine mounting for vibration dampening.
Transmission Type:
5-speed constant mesh, sequential manual gearbox
Optional Transmissions:
None for this era and model line.
Clutch Type:
Wet, multi-plate, diaphragm spring clutch
Primary Drive:
Duplex chain drive from engine to transmission
Final Drive:
Belt drive from transmission to rear wheel
Transmission Fluid Type:
Harley-Davidson recommends specific transmission lubricant; often a proprietary blend. API GL-4 gear oil or equivalent is common, but consult manual for exact spec.
Wheelbase:
Approximately 62.5 - 64.5 inches (1588 - 1638 mm), varies by specific FLST/FXST model.
Seat Height:
Approximately 26.0 - 27.5 inches (660 - 698 mm), varies by specific model.
Dry Weight:
Around 550 - 600 lbs (250 - 272 kg), varies by specific model and options.
Fuel Capacity:
Approximately 3.5 - 4.0 gallons (13.2 - 15.1 liters), varies by specific model.
Safety Certifications:
Manufactured to meet DOT and relevant motorcycle safety standards of the era. No formal crash ratings like cars.
Braking System:
Dual disc front brake, single disc rear brake. Hydraulic actuation. Often feature 4-piston calipers.
Lighting:
Halogen headlamp, LED (later models/optional) or incandescent tail/brake lights and turn signals.
Frame Construction:
Steel tube frame designed for stability and handling.
Infotainment Features:
Primarily mechanical and analog. Infotainment systems (radio, CD players) were not standard on these models, but aftermarket installations were common.
Driver Assistance Features:
None. Focus is on the riding experience and mechanical performance.
Connectivity Features:
None. Analog instrumentation and mechanical controls.
Oil Change Interval:
Typically every 2,500 - 5,000 miles (4,000 - 8,000 km) or annually, whichever comes first. Refer to manual for precise interval.
Spark Plug Replacement:
Approximately every 10,000 - 15,000 miles (16,000 - 24,000 km).
Drive Belt Check:
Regular inspection for wear and proper tension (typically every 5,000 miles).
Engine Oil Type:
Harley-Davidson 20W50 motorcycle oil (e.g., Harley-Davidson Genuine Motor Oil). Check manual for specific API classification and viscosity for the period.
Primary Chain Case Oil:
Harley-Davidson Primary Chain Lubricant or compatible primary lubricant.
Brake Fluid Type:
DOT 4 or DOT 5 (silicone-based) brake fluid, depending on original specification. Manual will specify which is correct for the model year.
Common Wear Items:
Clutch plates, wheel bearings, fork seals, carburetor performance, and battery life are common wear items.
Evo Engine Considerations:
While robust, Evo engines can develop oil leaks from gasket interfaces (e.g., crankcase, pushrod tubes) with age and mileage. Camshaft bearing upgrades were common in later years.
Electrical System Quirks:
Wiring harness integrity and connections can degrade over time, leading to intermittent electrical issues.
Heritage Summary:
Harley-Davidson, founded in 1903, is an iconic American motorcycle manufacturer renowned for its cruiser motorcycles, particularly the V-twin engine and its distinctive sound and styling.
Softail Introduction:
The Softail platform, introduced in 1983 (as a 1984 model), was designed to mimic the look of a hardtail frame with its shock absorbers hidden beneath the transmission, providing modern suspension comfort.
1985-1990 Changes:
This period saw the introduction and refinement of the Evolution (Evo) engine, replacing the Shovelhead. Significant updates included improved reliability, power delivery, and chassis refinements.
Manufacturing Location:
York, Pennsylvania, and Milwaukee, Wisconsin, USA.
Model Recognition:
The Harley-Davidson Softail platform, particularly with the Evolution engine, is highly regarded for its classic styling and riding experience, contributing to Harley-Davidson's enduring popularity.
Enthusiast Perception:
Considered a cornerstone of Harley-Davidson's lineup during the late 80s and early 90s, representing a significant step forward in refinement and reliability.
