Engine Mechanics:
Detailed disassembly, inspection, and reassembly of Shovelhead engine components (cylinders, pistons, heads, crankshaft, camshafts, valve train).
Fuel System:
Carburetor (likely Keihin butterfly or Linkert, depending on specific FLHS configuration) service, adjustment, and troubleshooting; fuel tank, lines, and petcock maintenance.
Ignition System:
Points ignition system service, timing adjustment, coil testing, spark plug selection, and troubleshooting.
Transmission And Drivetrain:
4-speed constant mesh transmission service, clutch operation and adjustment, primary chain maintenance, final drive belt/chain inspection and adjustment.
Electrical System:
Wiring diagrams, lighting systems, battery maintenance, charging system (generator/alternator), starter system, ignition switches, and accessory circuits.
Brakes:
Front and rear brake system service, hydraulic fluid changes, caliper and master cylinder overhaul, brake pad/shoe replacement, and drum brake adjustment.
Suspension And Steering:
Front fork (likely hydraulic with air assist or spring-over-oil) service, rear shock absorber inspection and replacement, steering head bearing adjustment.
Chassis And Frame:
Frame inspection, fork triple tree service, wheel bearing maintenance, axle removal and installation.
Bodywork And Trim:
Fender removal/installation, fuel tank mounting, seat adjustment, handlebar and control lever servicing, basic panel fitting.
Routine Maintenance:
Oil changes, filter replacements, spark plug checks, chain/belt lubrication and adjustment, brake adjustments, tire pressure checks.
Troubleshooting:
Diagnostic flowcharts and common problem-solving techniques for engine, electrical, and mechanical issues.
Major Repairs:
Complete engine rebuilds, transmission overhauls, fork seal replacements, brake caliper rebuilds.
Component Replacement:
Step-by-step guides for replacing specific parts like pistons, valves, bearings, clutches, ignition components, etc.
Depth Of Coverage:
Comprehensive, covering everything from basic rider maintenance to full engine and transmission overhauls.
Diagnostic Capabilities:
Detailed instructions for diagnosing electrical faults, carburetor issues, ignition timing problems, and mechanical noises.
Special Tools:
Identification of required special tools and their usage for specific procedures (e.g., flywheel puller, valve spring compressor).
Engine Type:
Harley-Davidson Shovelhead Evolution V-twin
Displacement:
74 cubic inches (1200cc) or 80 cubic inches (1340cc) depending on specific FLHS variant for 1981.
Bore X Stroke:
Varies by displacement: 74ci (3.4375 in x 4.00 in), 80ci (3.50 in x 4.25 in)
Compression Ratio:
Typically around 7.0:1 to 8.0:1 for Shovelheads of this era.
Valve Train:
Overhead Valve (OHV), pushrod actuated.
Horsepower:
Estimated 55-65 HP, highly dependent on tuning and exact configuration.
Torque:
Estimated 65-75 lb-ft, also dependent on tuning.
Carburetor Type:
Likely Keihin butterfly carburetors (e.g., CV or butterfly models) or potentially a Linkert depending on late-model application.
Fuel Type:
Unleaded gasoline, octane rating recommendation will be specified in the manual (typically 87-91 AKI).
Oil Type:
Viscosity and type will be specified, commonly SAE 20W-50 motorcycle oil.
Oil Capacity:
Approx. 3-4 quarts (depending on filter).
Ignition Type:
Battery and Coil with points and condenser.
Cooling Method:
Air-cooled
Transmission Type:
4-speed constant mesh, foot shift with heel-toe lever.
Optional Transmissions:
None for this model year/type.
Clutch Type:
Wet, multi-plate, cable-actuated.
Primary Drive:
Duplex chain drive from engine to transmission.
Final Drive:
Belt drive (typically 132-tooth belt).
Transmission Oil Type:
Harley-Davidson recommends specific transmission fluids; SAE 75W-90 or similar gear oil often used, consult manual for exact spec.
Crash Test Ratings:
Not applicable to motorcycles in the traditional automotive sense.
Braking System:
Dual disc front, single disc rear (standard on FLHS).
Lighting:
Halogen headlight, taillight, brake light, turn signals.
Frame Construction:
Steel frame with robust construction.
Rider Protection:
Handlebar controls, footboards, seat providing rider contact points.
Oil Change Interval:
Typically every 2,000-3,000 miles or annually, as per original service manual recommendations.
Primary Chain Tensioner Adjustment:
Check/adjust every 5,000-10,000 miles.
Valve Lash Adjustment:
Recommended every 5,000-10,000 miles, or as needed for optimal performance.
Spark Plug Replacement:
Every 5,000-10,000 miles, or as indicated by wear.
Engine Oil Viscosity:
SAE 20W-50 recommended for air-cooled V-twins of this era.
Transmission Oil Type:
Consult manual for specific H-D or equivalent gear oil.
Brake Fluid Type:
DOT 4 (typically for hydraulic systems of this period).
Shovelhead Common Issues:
Oil leaks (especially rear main seal), oil consumption, primary chain adjuster wear, valve seat recession (with unleaded fuel), points ignition timing drift.
Electrical Issues:
Aging wiring harnesses, voltage regulator failures, charging system issues.
Transmission Issues:
Clutch drag, shift linkage adjustment.
Brand Origin:
Founded in Milwaukee, Wisconsin, USA in 1903.
Brand Reputation:
Iconic American motorcycle manufacturer renowned for V-twin engines and distinctive styling.
Shovelhead Era:
Shovelhead engine was produced from 1966 to 1984, a significant period in Harley-Davidson's history.
Flhs Designation:
FLHS typically denoted a 'Sport-Touring' model, often featuring a fairing and saddlebags.
Production Years:
The Shovelhead engine was produced from 1966 to 1984. The FLHS model was produced during various years within this range, with 1981 being a specific target.
Manufacturing Location:
Milwaukee, Wisconsin, USA.