Dedicated Subsystem WorkbenchPlatform Gen: 1984–1999

1986 Harley Davidson Evolution 80ci (Dyna / Softail / FXR / Touring) Cylinder Compression & Leakdown Diagnostic Engine

Factory compression specs for 1986 Harley Davidson Evolution 80ci (Dyna / Softail / FXR / Touring): standard pressure 140 - 160 PSI (965 - 1103 kPa), service limit 120 PSI, dry vs wet test diagnostics and acoustic leak stethoscope.

Technical PassportOEM VERIFIED

Engine

1340cc

Cooling

Air-Cooled

Final Drive

Belt Drive

Engine Oil

2.84 L (3.00 US qt)

Spark Plug

HD 5R6A / Champion RN12YC / NGK BPR5ES

Front Tire

MT90B16 (Touring) / 100/90-19 (Dyna) / MH90-21 (FXST Softail)

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Gen 1984–1999

Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 1984 through 1999.

Select Model Year:(Active: 1986)
16 Production Years (1984–1999)

1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Suggested Items4 Verified Workshop Consumables Available for this Job

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Cylinder Compression & Leakdown Diagnostic Engine

Multi-Cylinder Dry vs. Wet Test Bench, Differential Pressure Regulator & Acoustic Stethoscope Locator

Ratio: 8.5:1Std: 140-160 PSILimit: 120 PSIWhip Adapter: 14 mm × 1.25

Diagnostic Presets:

Cyl #1 (Front)IN-SPEC

153PSI(1055 kPa)

Cyl #2 (Rear)IN-SPEC

151PSI(1041 kPa)

Cross-Cylinder Variance: Δ 2 PSI (OEM Limit: ≤ 15 PSI)

VARIANCE IN-SPEC

All cylinders demonstrate strong, balanced mechanical sealing. Piston ring packs, cylinder cross-hatch, and valve seats are within factory specification.

Official Workshop Manual Compression Test Protocol

Step 0 of 5 Completed

Step 1: Engine Operating Temperature

Run engine until coolant reaches 60°C - 80°C (140°F - 176°F). Cylinder expansion brings rings and pistons to true operating clearances.

Step 2: Spark Plug Removal & Port Clean

Blow compressed air around spark plug wells to eject grit, then remove all spark plugs. Thread in 14 mm × 1.25 whip adapter hand-tight with fresh O-ring.

Step 3: Wide-Open Throttle (WOT) Lock

Hold throttle grip fully wide open (or lock throttle bodies open) to eliminate intake butterfly vacuum restriction and ensure 100% volumetric cylinder filling.

Step 4: Battery Tender Voltage Stabilization

Connect a 12V shop battery tender or booster. Starter must sustain uninterrupted cranking speed (250 RPM) to build maximum dynamic stroke pressure.

Step 5: Crank 4-6 Compression Strokes

Engage starter until gauge needle ceases rising (typically 4 to 6 strokes). Record maximum peak pressure and compare against the OEM limits above.

Official NHTSA Safety Recalls & Technical Bulletins

0 Open Campaigns (Clean)

U.S. Department of Transportation compliance database (Title 49 U.S.C. Chapter 301).

Verify VIN on NHTSA.gov

No Active Federal Safety Recalls Reported

The U.S. DOT National Highway Traffic Safety Administration (NHTSA) records zero open safety recall campaigns for the 1986 Harley Davidson Evolution 80ci (Dyna / Softail / FXR / Touring) platform. Always check your individual 17-digit VIN at an authorized dealership or via NHTSA.gov for individual recall completions.

Explore Other Subsystems for this 1986 Harley Davidson Evolution 80ci (Dyna / Softail / FXR / Touring)

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Subsystem Guide/torques

Fastener Torques

Engine drain plug, axle spindles, caliper mounts, triple clamp pinch bolts & thread lubrication derating guide.

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Subsystem Guide/fluids

Fluids & Capacities

Oil: 2.84 L (3.00 US qt) • Coolant: N/A • Brake: DOT 5 Silicone-Based (Purple) - strictly NEVER mix DOT 5 with glycol DOT 4

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Subsystem Guide/fuses-relays

Fuses & Relays

Main: 30A Main Thermal Circuit Breaker • Location: N/A

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Subsystem Guide/valves

Valve Clearances

Intake: N/A mm • Exhaust: N/A mm

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Subsystem Guide/fuel-delivery

Fuel Delivery & TB Sync

Idle: N/A • Rail Pressure: N/A • Vacuum: N/A

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Subsystem Guide/electrical

Charging & Battery

Battery: YTX20L-BS (Dyna/Softail) / Y60-N24AL-B (Touring) • CCA: 310 • Regulated: 13.8 - 14.4 V DC at 3,000 RPM

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Subsystem Guide/tires

Tires & Gearing

Front: MT90B16 (Touring) / 100/90-19 (Dyna) / MH90-21 (FXST Softail) • Rear: MT90B16 or 130/90B16

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Subsystem Guide/suspension

Suspension & Sag

Front Travel: 120 mm • Rear Travel: 76 mm

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Subsystem Guide/maintenance

Maintenance Schedule

Oil: Every 2,500 - 5,000 mi (4,000 - 8,000 km) mi • Valves: N/A • Plugs: Every 5,000 mi (8,000 km) mi

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