Factory Workshop SpecificationsPlatform Gen: 2020–2024
2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight) Specifications & Consumables
Official workshop technical reference: fluid capacities, spark plug codes, drive chain specs, and tire inflation pressures.
Gen 2020–2024
Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 2020 through 2024.
Engine
1868cc
Drive
Chain
Cooling
Air/Oil-Cooled
Engineering Subsystem Workbenches & Calculators
Dedicated deep-dive diagnostic tools, torque matrices, wiring pinouts, and calculators tailored for 2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight).
Subsystem Guide/torques
Fastener Torques
Engine drain plug, axle spindles, caliper mounts, triple clamp pinch bolts & thread lubrication derating guide.
Open Dedicated Workbench →
Subsystem Guide/fluids
Fluids & Capacities
Oil: 4.70 L (5.00 US qt) • Coolant: N/A • Brake: DOT 4
Open Dedicated Workbench →
Subsystem Guide/fuses-relays
Fuses & Relays
Main: 50A Maxi-Fuse • Location: Under rider seat
Open Dedicated Workbench →
Subsystem Guide/compression
Compression & Leakdown
Ratio: 10.2:1 • Std: 180-225 PSI • Limit: 140 PSI
Open Dedicated Workbench →
Subsystem Guide/valves
Valve Clearances
Intake: N/A mm • Exhaust: N/A mm
Open Dedicated Workbench →
Subsystem Guide/fuel-delivery
Fuel Delivery & TB Sync
Idle: N/A • Rail Pressure: N/A • Vacuum: N/A
Open Dedicated Workbench →
Subsystem Guide/electrical
Charging & Battery
Battery: YTX20HL-BS (310 CCA) • Regulated: 14.0 - 14.6 V DC
Open Dedicated Workbench →
Subsystem Guide/tires
Tires & Gearing
Front: 110/90B19 (36 PSI) • Rear: 180/70B16 (42 PSI)
Open Dedicated Workbench →
Subsystem Guide/suspension
Suspension & Sag
Front Travel: 130 mm • Rear Travel: 112 mm
Open Dedicated Workbench →
Subsystem Guide/maintenance
Maintenance Schedule
Oil: Every 5,000 miles (8,000 km) mi • Valves: Every 26,600 mi • Spark Plugs: Every 10,000 miles (16,000 km) mi
Open Dedicated Workbench →
Fluids & Service Capacities
Shop Fluids →Engine Oil (Drain & Filter Change)4.70 L (5.00 US qt)
Engine Oil (Drain Only)4.25 L (4.50 US qt)
Recommended Oil Viscosity20W-50 SYN3 Full Synthetic or H-D 360
Coolant System CapacityN/A
Brake Fluid StandardDOT 4
Drivetrain, Chain & Gearing
Shop Chains & Sprockets →Drive Chain PitchN/A
Chain Link CountN/A
Front Sprocket TeethN/A
Rear Sprocket TeethN/A
Final Drive ConfigurationBelt Drive
Ignition & Electrical Specifications
Shop Plugs & Batteries →OEM Spark Plug Part NumberHarley 6R10 / NGK CPR7EA-9
Electrode Spark Plug Gap0.8 - 0.9 mm (0.031 - 0.035 in)
OEM Battery Reference CodeYTX20HL-BS
Battery Output & Rating12V 18Ah 310 CCA
Spark Plug Inspection Interval10,000 miles (16,000 km)
Wheels, Tires & Inflation Pressures
Shop Tires →Front Tire Dimensions110/90B19
Cold Front Inflation Pressure36 PSI (Cold)
Rear Tire Dimensions180/70B16
Cold Rear Inflation Pressure40 PSI (Cold)
OEM Wheel Rim Widths (F / R)3.50" / 5.50"
Critical Fastener Torque Tolerances
FSM Certified SpecsFactory workshop tightening torque ratings for axles, calipers, engine plugs, and triple clamps.
Lube:
| Fastener / Component | Torque (N·m) | Service Note & Thread Guidance | System |
|---|---|---|---|
Engine Oil Drain Bolt 1/2"-20 O-Ring Boss• 5/8" Socket | 24 N·m (17.7 ft-lb) | Hand-spin until washer seats flush against sump; torque in single continuous stroke. WARNING: Over-torquing strips soft aluminum oil pans requiring permanent Heli-Coil or Time-Sert insert repair. | Engine / Drive |
Engine Oil Filter (Spin-on / Cover) 3/4"-16• 14-Flute Filter Cap Wrench• Engine Oil (Pre-Lube) | 17 N·m (12.5 ft-lb) | Lubricate rubber O-ring with fresh clean engine oil before spinning on. Tighten until gasket contacts, then advance 2 to 2.5 full turns. WARNING: Never install dry rubber seal. Dry gaskets pinch, buckle, and spray oil onto the rear tire at highway speed. | Engine / Drive |
Spark Plugs (Cold Engine) 12 mm × 1.25 (14mm Hex)• 5/8 in Spark Plug Socket• None (Clean Dry Plated Threads) | 20 N·m (14.8 ft-lb) | Hand-thread all plugs using rubber hose extension until seated. Torque strictly on cold engine (≤ 35°C / 95°F). WARNING: Modern NGK/Denso trivalent plated threads require zero anti-seize. Torquing hot heads strips aluminum spark plug threads. | Engine / Drive |
Clutch Pressure Plate Spring Bolts M6 × 1.0• 10 mm Socket / 8 mm Hex | 12 N·m (8.9 ft-lb) | Criss-cross diagonal pattern across 3 stages (finger tight → 5 N·m → 10 N·m) to seat pressure plate completely flat. WARNING: Uneven tightening tilts the clutch pressure plate, snapping delicate aluminum clutch basket lifter posts. | Engine / Drive |
Clutch Outer Case Cover Bolts M6 × 1.0• 8 mm Hex Socket | 10 N·m (7.4 ft-lb) | Criss-cross pattern starting from center bolts moving outward. Verify dowel alignment pins seat fully. WARNING: M6 bolts into aluminum engine cases snap easily. Always use a precision low-range 1/4" drive torque wrench. | Engine / Drive |
Alternator / Stator Cover Bolts M6 × 1.0• 8 mm Hex Socket• Medium Strength (Blue 242/243) on Stator Wire Bracket | 10 N·m (7.4 ft-lb) | Criss-cross pattern. Apply thin bead of ThreeBond / RTV sealant only at rubber grommet wire passthrough. WARNING: Powerful magnetic rotor will violently snap the cover against the engine case during installation; keep fingers clear. | Engine / Drive |
Front Transmission Belt Pulley Nut 1-7/8" Thread• 1-7/8" Deep Socket• High Strength (Red 271/272) | 142 N·m (104.7 ft-lb) | Torque to 50 ft-lb, then advance 35°–45° further. Lock with factory locking plate and screws. WARNING: Reverse / left-hand thread on selected models. Verify thread rotation direction before applying breaker bar. | Engine / Drive |
Rear Drive Wheel Pulley Bolts 7/16"-14 Grade 8• 5/8" Socket• High Strength (Red 271/272) | 81 N·m (59.7 ft-lb) | Star pattern in 2 stages: initial seat to 35 N·m (26 ft-lb), then final 81 N·m (60 ft-lb). WARNING: Factory workshop manuals mandate replacing pulley bolts every time they are removed. Never reuse stretched pulley bolts. | Engine / Drive |
Front Wheel Axle Spindle / Bolt 3/4"-16• 15/16" Socket• None (Clean Dry Threads / Light Grease on Shaft) | 88 N·m (64.9 ft-lb) | Torque axle bolt first while pinch bolts remain loose. Pump front forks 3–4 times before torquing pinch bolts. WARNING: Torquing pinch bolts before axle nut causes fork binding, stiction, and severe front brake shudder. | Chassis / Susp |
Front Axle Fork Bottom Pinch Bolts M8 × 1.25• 6 mm Allen / 12 mm Socket | 23 N·m (17 ft-lb) | Dual pinch forks: alternate tightening between inner and outer bolt 3 times until wrench clicks on both without moving. WARNING: Tightening one bolt relaxes the adjacent bolt. Failure to alternate causes pinch bolts to work loose under road vibration. | Chassis / Susp |
Rear Axle Castle / Flange Nut 1"-14 / M25• 36 mm Socket• None (Factory Locknut / Cotter Pin) | 135 N·m (99.6 ft-lb) | Push wheel forward against adjusters while torquing. Insert fresh cotter pin or R-clip through castle slot. WARNING: Under-torquing allows axle cocking, throwing wheel out of alignment; over-torquing crushes wheel bearing spacer tubes. | Chassis / Susp |
Rear Shock Upper & Lower Mount Bolts M10 × 1.25• 14 mm / 17 mm Socket• Medium Strength (Blue 242/243) | 44 N·m (32.5 ft-lb) | Torque bolts with rear suspension loaded at static ride height (wheel on ground), not at full hanging droop. WARNING: Torquing shock eyelet rubber/spherical bushings at full droop locks preload twist into bushings, causing premature bushing tear. | Chassis / Susp |
Swingarm Pivot Shaft Nut M18 × 1.5• 22 mm / 27 mm Socket | 65 N·m (47.9 ft-lb) | Set swingarm pivot thrust collar clearance with spanner tool before torquing central through-shaft nut. WARNING: Incorrect pivot preload crushes needle bearings or induces lateral swingarm wobble and high-speed tank-slappers. | Chassis / Susp |
Upper Triple Clamp (Fork Bridge) Pinch Bolts M8 × 1.25• 6 mm Allen / 12 mm Socket | 26 N·m (19.2 ft-lb) | Verify fork tube height / stanchion protrusion above top bridge matches factory spec with vernier caliper before tightening. WARNING: Uneven fork tube heights alter chassis steering geometry, trail, and induce high-speed head-shake. | Controls |
Lower Triple Clamp Pinch Bolts M8 × 1.25• 6 mm Allen / 12 mm Socket | 23 N·m (17 ft-lb) | Alternate between upper and lower bolt on each side 3 times to achieve uniform clamping without localized tube deformation. WARNING: CRITICAL: Overtightening lower clamp pinches the outer fork slider oval, locking fork bushings and causing severe suspension stiction. | Controls |
Handlebar Riser Clamps / Clip-on Clamps 5/16"-18• 1/4" Allen | 24 N·m (17.7 ft-lb) | MANDATORY ZERO-GAP RULE: Tighten front bolts until clamp casting touches bottom casting with zero gap; then torque rear bolts to spec. WARNING: Leaving a gap at the front bolts allows handlebars to slip under sudden hard emergency braking. | Controls |
Steering Stem Head Nut M28 × 1.0• 30 mm / 36 mm Socket | 110 N·m (81.1 ft-lb) | Ensure upper triple clamp pinch bolts are loose when torquing stem nut to prevent binding the steering bearings. WARNING: This nut clamps the top bridge; steering head bearing preload is adjusted separately via the lower castle spanner ring. | Controls |
Front Brake Master Cylinder Clamp Bolts M6 × 1.0• 8 mm Hex / 5 mm Allen | 10 N·m (7.4 ft-lb) | Align "UP" arrow mark on split clamp upward. Tighten upper bolt first until clamp seats flush; then torque lower bolt to 10 N·m. WARNING: Tightening bottom bolt first pinches the reservoir casting unevenly, cracking master cylinder clamp ears. | Controls |
Front Brake Caliper Mount Bolts 3/8"-16 High Tensile• 10 mm 12-Point Socket• Medium Strength (Blue 242/243) / Factory Micro-Encapsulated | 45 N·m (33.2 ft-lb) | Radial calipers: tighten upper and lower bolts in two equal stages (20 N·m, then final spec). WARNING: Radial caliper mounting threads tap directly into aluminum fork bottoms. Never use pneumatic/electric impact guns. | Braking |
Rear Brake Caliper Mount / Bracket Bolts M8 × 1.25• 12 mm Socket / 6 mm Allen• Medium Strength (Blue 242/243) | 23 N·m (17 ft-lb) | Ensure caliper bracket sliding torque arm slot engages swingarm tab cleanly before tightening. WARNING: Unengaged bracket tabs allow rear caliper to rotate with disc during braking, shearing brake lines. | Braking |
Front Brake Disc Rotor Bolts M8 × 1.25 Low-Profile Shoulder• 6 mm Allen / T40 Torx• Medium Strength (Blue 242/243 Mandatory) | 24 N·m (17.7 ft-lb) | Clean wheel hub female threads with solvent; apply 2 drops of Blue 243. Tighten in criss-cross star pattern across 2 stages. WARNING: A loose brake rotor bolt can back out and impact the front fork leg, instantly locking the front wheel. | Braking |
Rear Brake Disc Rotor Bolts M8 × 1.25 / M10 × 1.25• 6 mm Allen / T40 Torx• Medium Strength (Blue 242/243 Mandatory) | 47 N·m (34.7 ft-lb) | Criss-cross star pattern. Ensure disc sits 100% flat against wheel hub register with zero trapped debris. WARNING: Trapped dirt under rotor mounting flange causes severe brake pedal pulsation and lateral rotor runout. | Braking |
Hydraulic Brake Line Banjo Bolts 3/8"-24 / 7/16"-24• 12 mm / 14 mm Hex Socket• None (Clean Dry with Fresh Copper Washers) | 30 N·m (22.1 ft-lb) | Always replace the two copper/aluminum crush washers per banjo joint. Never reuse crushed washers. WARNING: Over-torquing shears the cross-drilled fluid passage inside the banjo bolt, destroying the caliper casting. | Braking |
Caliper Hydraulic Bleed Screws M7 × 1.0 / M8 × 1.25• 8 mm / 10 mm Line Wrench | 6 N·m (4.4 ft-lb) | Use 6-point flare-nut / line wrench to prevent rounding soft hex. Snug firmly until seated against conical seat. WARNING: Overtightening distorts the internal conical sealing point, causing persistent hydraulic fluid weeping. | Braking |
Technical Standard:Always calibrate torque wrenches prior to critical chassis fastening. Values reflect clean, dry threads unless threadlocker or anti-seize is specifically noted.
Tire Engineering & Multi-Scenario Pressure Matrix
ETRTO ValidatedInflation targets calibrated across operating modes, verified rim width ranges, and certified alternate sizes.
Multi-Scenario Inflation Pressures
Solo Street / CommutingCold Baseline
Front: 36 PSI
Rear: 40 PSI
Two-Up Passenger & LuggageMax Load
Front: 38 PSI
Rear: 42 PSI
Off-Highway / Terrain Pressure
Maintain OEM cold baseline for street transfers; adjust -2 to -4 PSI for loose terrain.
Rim Geometry & ETRTO Envelopes
Front Wheel
OEM Rim Width:3.50"
Permissible Envelope:3.50" - 3.75"
Rear Wheel
OEM Rim Width:5.50"
Permissible Envelope:5.50" - 6.00"
Operating outside ETRTO envelope width alters crown radius, accelerates shoulder wear, and impacts lean stability.
Factory Dimensions & Verified Alternates
Factory Standard Sizes
Front:110/90B19
Rear:180/70B16
Verified Alternate Fitments
Factory Standard
Alternate profiles verified for swingarm, chain guard, and fender clearances.
Final Drive Gearing & Speed/RPM Calculator
Belt DriveFactory reduction ratios, interactive sprocket gearing simulator, 6th gear cruising RPM matrix, and swingarm chain adjustment tolerances.
Drive Architecture
Poly-Chain Carbon Belt
OEM Pulleys
32T Transmission / 66T Wheel
OEM Final Ratio
2.063 : 1
Belt Teeth & Width
142T • 1.000 in (25.4 mm) Carbon Core
Cold Tension Deflection
1/4 - 5/16 in (6.4 - 7.9 mm) deflection with 10 lbs force
Quick Gearing Presets
Front Transmission PulleyStock: 32T
32 Teeth
Factory teeth count
Rear Wheel Belt PulleyStock: 66T
66 Teeth
Factory teeth count
Drive Ratio & Torque Impact
Calculated Final RatioStock: 2.063
2.063 : 1-0.02%
Drivetrain Torque Delta
0.0% Taller Gearing (Reduced Highway RPM)
Lengthens transmission gears, lowers sustained engine RPM on motorways, and reduces engine buzz and vibration.
Countershaft Speedo Variance:+0.0%
At 70.0 mph indicated speed, true vehicle ground speed is 70.0 mph.
Cruising Engine RPM in 6th Gear
60 MPH
Stock: 2,172 RPM
2,171 RPM
-1 RPM
70 MPH
Stock: 2,534 RPM
2,533 RPM
-1 RPM
80 MPH
Stock: 2,896 RPM
2,895 RPM
-1 RPM
Calculated using factory 6th gear ratio (1), primary reduction (1.353), and 180/70B16 rolling circumference.
Belt Tension & Deflection Spec
Cold Deflection Tolerance
1/4 - 5/16 in (6.4 - 7.9 mm) deflection with 10 lbs force
Check tension using a 10-lb belt tension gauge at the lower belt run midpoint window on the side stand.
Belt Architecture
142T • 1.000 in (25.4 mm) Carbon Core
Inspect poly-chain carbon teeth for stone cuts and check tension on side stand cold
Recommended Belt: Gates Poly Chain Carbon Drive Belt
Factory Chassis Geometry
Chassis Alignment, Drive Tension & Rear Axle Calibration
Precision workshop alignment tools, dynamic drive tension tolerances, and axle spindle calibration for the 2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight).
Belt Drive Architecture
Secondary Belt Deflection & 10-lb Tension Calibration
FACTORY BELT DEFLECTION SPEC:
1/4 - 5/16 in (6.4 - 7.9 mm) deflection with 10 lbs force
Measure cold deflection with a spring-loaded belt tension tool applying exactly 10 lbs (4.5 kg) of upward force at the lower belt run inspection window on jiffy stand.
CARBON BELT TOOTH & FLANGE INSPECTION:
142T • 1.000 in (25.4 mm) Carbon Core
Inspect polyurethane cog teeth for stone gouges or embedded gravel. Verify rear pulley chrome flanges show even belt tracking without edge fraying.
Factory Valve Clearance & Shim Calculator
OEM Workshop TolerancesCylinder head valve lash specifications, timing TDC mark alignments, and interactive replacement shim calculation engine.
Adjustment Mechanism: 9.48 mm
Active Valve Range (INTAKE)
0.12 - 0.20 mm
0.005 - 0.008 in
Nominal Mid-Spec Target
0.16 mm
Ideal cold lash assembly setting
Shim Diameter / Tappet
9.48 mm
Bucket-and-shim interface
Measurement Condition
Cold Engine (≤ 35°C / 95°F)
TDC compression stroke only
Interactive Shim Sizing Calculation Engine: New Shim = Current Shim + (Measured Clearance - Target Clearance)
mm
Factory intake tolerance: 0.12 - 0.20 mm
mm
Measured with micrometer or read laser-etched face
TDC Crankshaft Timing Index
Align crankshaft TDC mark with engine timing index pointer
Feeler Gauge Technique
Angled blade feeler gauge (cold engine ≤ 35°C / 95°F)
Cylinder Compression & Leakdown Diagnostic Engine
Multi-Cylinder Dry vs. Wet Test Bench, Differential Pressure Regulator & Acoustic Stethoscope Locator
Ratio: 10.2:1Std: 180-225 PSILimit: 140 PSIWhip Adapter: M10 x 1.25
Automatic Compression Release (ACR) Solenoids
M8 heads utilize ECU-controlled electronic ACR solenoids in spark plug wells. Disconnect ACR harness plugs during compression testing to measure true mechanical cylinder pressure, or readings will register 30-40 PSI below actual.
Diagnostic Presets:
Cyl #1 (Front)IN-SPEC
209PSI(1441 kPa)
Cyl #2 (Rear)IN-SPEC
207PSI(1427 kPa)
Cross-Cylinder Variance: Δ 2 PSI (OEM Limit: ≤ 15 PSI)
VARIANCE IN-SPECAll 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 CompletedStep 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 M10 x 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 (300 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.
Air-Cooled Engine Architecture
Engine Cooling System Hydraulics, Thermostat & Antifreeze Calibration
Air and oil cooling thermal management and fin maintenance for the 2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight).
Cooling Configuration
Air/Oil-Cooled Milwaukee-Eight V-Twin
Oil Heat Exchanger: Front Downtube Factory Aluminum Oil Radiator with Thermostat
Max Cylinder Head Temp (Infrared)
215°C
Sustained operation above this threshold breaks down engine oil viscosity and glazes cylinder walls.
Engine Oil Drain Plug Torque
25 N·m
Dry-sump / wet-sump drain bolt with fresh crush washer or O-ring.
Spark Plug Cold Torque
20 N·m
Torque into cold aluminum cylinder head to prevent stripped spark plug threads.
Workshop Cooling Fin Maintenance Protocol
Clean oil cooler radiator matrix mounted between front frame downtubes. Check oil line quick-connect fittings for weeping. Keep cylinder fins free of caked road mud. Never use high-pressure pressure washers on cylinder fins or oil coolers as the high-pressure water stream will fold delicate cooling fins flat and restrict engine thermal dissipation.
FSM Induction Calibration45° V-Twin (Milwaukee-Eight) (2 Throttle Bores)
Fuel Delivery, Throttle Body Synchronization & Manometer Balancer
Factory intake depression specifications (260 mmHg), electronic fuel pump pressure testing (58 PSI), injector resistance, and interactive multi-column manometer balancing.
Warm Idle: 850 - 950 RPM
Quick Workshop Diagnostic Presets
Simulate Throttle Linkage Asymmetry, Hunting Idle, or Intake Boot Vacuum Leaks
OPTIMAL SYNCHRONIZATION: BALANCED (Δ ≤ 15 mmHg)
Diagnostics:Max Differential: Δ 0 mmHg (Factory Max Tolerance: ≤ 15 mmHg)
All 2 throttle plates pull uniform intake depression within factory engineering tolerance (≤ 15 mmHg / 2.00 kPa). Delivers immediate linear throttle pickup, silky smooth idle, uniform cylinder torque pulses, and balanced exhaust temperatures.
Workshop Multi-Column Fluid Manometer
Damped intake depression columns. Target spec: 260 mmHg (±15 mmHg) at warm idle (850 - 950 RPM).
Reference: Single 55mm Electronic Throttle Body (Dual Cylinder Common Plenum)
Mechanism: Bypass Screws
CYL #1
MASTER REF
260mmHg
34.7 kPa · 10.2 inHg
±0 mmHg (Exact Target)
Fixed Reference Master. Synchronize all slave throttle bodies to match this column.
CYL #2
SLAVE BORE
260mmHg
34.7 kPa · 10.2 inHg
±0 mmHg (Exact Target)
Vacuum Take-Off Ports: Rubber plug capped vacuum test port on intake manifold branch
Damping Protocol: Restrictor valves must be adjusted until columns oscillate no more than ±5 mmHg per intake stroke.
Fuel Pump Pressure & 5-Min Hold Test
EFI Pressure RailRunning Fuel Pressure
58 PSI(4.00 bar)
OEM Running Spec
58 PSI (±3 PSI)
PASS: WITHIN OEM RUNNING SPEC
Fuel pump delivery pressure is 58 PSI (Factory spec: 58 PSI ± 3 PSI / 4 bar). High-pressure regulator and pump rotor operating within factory design threshold.
Connect mechanical gauge to the quick-disconnect fuel rail fitting using an OEM banjo or T-adapter.
Fuel Injector Resistance & Induction Specs
Multimeter Bench CheckOEM Injector Solenoid Resistance
12.5 - 13.5 Ω at 20°C
Measure across injector 2-pin harness socket with ignition OFF. Internal coil resistance increases by ~0.4% per °C rise above 20°C (68°F). Replace injector if resistance reads open (> 100 kΩ) or shorted (< 2 Ω).
Bore Diameter
55 mm
Operating Temp
80°C (176°F)
Induction Type
Sequential Port Fuel Injection (ESPFI) with 55mm Electronic Throttle Body
Injector O-rings must be lubricated with a light coat of clean engine oil before seating into fuel rail.
4-Step Throttle Body Synchronization Protocol
Official workshop manual step-by-step checklist. Mark each step as you complete it on the workbench.
0 of 4 Steps Complete
1CLICK TO MARK DONE
Engine Pre-Flight Conditioning
Check and adjust valve clearances to spec before attempting sync. Ensure air filter is clean, spark plugs are fresh, and engine is fully warmed to operating temperature (80°C–90°C).
2CLICK TO MARK DONE
Manometer Connection & Damping
Connect 2-column liquid or digital manometer hoses to Rubber plug capped vacuum test port on intake manifold branch. Adjust in-line hose restrictor valves to dampen rapid intake pulsation until fluid columns stabilize.
3CLICK TO MARK DONE
Balance Screw Calibration
With engine idling at 850 - 950 RPM, identify Single 55mm Electronic Throttle Body (Dual Cylinder Common Plenum). Adjust Common throttle bore with Electronic Throttle Control (ETC) and manifold air pressure balance until all cylinder columns are within 15 mmHg (2.00 kPa) of the master reference.
4CLICK TO MARK DONE
Throttle Blip & Locknut Verification
Blip throttle to 3,000 RPM 2–3 times and verify columns return evenly to idle balance. Tighten any balance screw locknuts securely, re-install rubber vacuum sealing caps, and verify idle speed.
Factory OEM Fastener Torque Matrix
Multi-System Fastener Torque Quick-Finder & Bolt Grade Matrix
Tightening torques, thread dimensions, socket drive sizes, threadlocker specifications, and sequential tightening procedures for the 2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight).
Interactive Thread Lubrication & Torque Derating Calculator
Prevent Stripped Threads: Convert Dry Factory Torque Specs to Lubricated Wrench Settings
100% FACTORY DRY SPEC
Torque wrenches measure rotational friction, not axial bolt stretch. Applying dry factory torque specs to threads lubricated with anti-seize, threadlocker, or oil reduces thread friction, causing bolt tension to increase 30%–50% at the same wrench setting and stripping soft aluminum motorcycle castings. Select your active fastener thread condition below:
Dry Threads (Factory Baseline): Clean, dry threads with zero lubricant. 100% of factory torque spec.
Engine & DrivetrainNone (Clean Dry)
Engine Oil Drain Bolt
Tightening Torque
24 N·m
17.7 ft-lb
Thread Dimension
1/2"-20 O-Ring Boss
Socket / Drive
5/8" Socket
Sequence: Hand-spin until washer seats flush against sump; torque in single continuous stroke.
CRITICAL CAUTION: Over-torquing strips soft aluminum oil pans requiring permanent Heli-Coil or Time-Sert insert repair.
Engine & DrivetrainEngine Oil (Pre-Lube)
Engine Oil Filter (Spin-on / Cover)
Tightening Torque
17 N·m
12.5 ft-lb
Thread Dimension
3/4"-16
Socket / Drive
14-Flute Filter Cap Wrench
Sequence: Lubricate rubber O-ring with fresh clean engine oil before spinning on. Tighten until gasket contacts, then advance 2 to 2.5 full turns.
CRITICAL CAUTION: Never install dry rubber seal. Dry gaskets pinch, buckle, and spray oil onto the rear tire at highway speed.
Engine & DrivetrainNone (Clean Dry Plated Threads)
Spark Plugs (Cold Engine)
Tightening Torque
20 N·m
14.8 ft-lb
Thread Dimension
12 mm × 1.25 (14mm Hex)
Socket / Drive
5/8 in Spark Plug Socket
Sequence: Hand-thread all plugs using rubber hose extension until seated. Torque strictly on cold engine (≤ 35°C / 95°F).
CRITICAL CAUTION: Modern NGK/Denso trivalent plated threads require zero anti-seize. Torquing hot heads strips aluminum spark plug threads.
Engine & DrivetrainNone (Clean Dry)
Clutch Pressure Plate Spring Bolts
Tightening Torque
12 N·m
106 in-lb
Thread Dimension
M6 × 1.0
Socket / Drive
10 mm Socket / 8 mm Hex
Sequence: Criss-cross diagonal pattern across 3 stages (finger tight → 5 N·m → 10 N·m) to seat pressure plate completely flat.
CRITICAL CAUTION: Uneven tightening tilts the clutch pressure plate, snapping delicate aluminum clutch basket lifter posts.
Engine & DrivetrainNone (Clean Dry)
Clutch Outer Case Cover Bolts
Tightening Torque
10 N·m
89 in-lb
Thread Dimension
M6 × 1.0
Socket / Drive
8 mm Hex Socket
Sequence: Criss-cross pattern starting from center bolts moving outward. Verify dowel alignment pins seat fully.
CRITICAL CAUTION: M6 bolts into aluminum engine cases snap easily. Always use a precision low-range 1/4" drive torque wrench.
Engine & DrivetrainMedium Strength (Blue 242/243) on Stator Wire Bracket
Alternator / Stator Cover Bolts
Tightening Torque
10 N·m
89 in-lb
Thread Dimension
M6 × 1.0
Socket / Drive
8 mm Hex Socket
Sequence: Criss-cross pattern. Apply thin bead of ThreeBond / RTV sealant only at rubber grommet wire passthrough.
CRITICAL CAUTION: Powerful magnetic rotor will violently snap the cover against the engine case during installation; keep fingers clear.
Engine & DrivetrainHigh Strength (Red 271/272)
Front Transmission Belt Pulley Nut
Tightening Torque
142 N·m
104.7 ft-lb
Thread Dimension
1-7/8" Thread
Socket / Drive
1-7/8" Deep Socket
Sequence: Torque to 50 ft-lb, then advance 35°–45° further. Lock with factory locking plate and screws.
CRITICAL CAUTION: Reverse / left-hand thread on selected models. Verify thread rotation direction before applying breaker bar.
Engine & DrivetrainHigh Strength (Red 271/272)
Rear Drive Wheel Pulley Bolts
Tightening Torque
81 N·m
59.7 ft-lb
Thread Dimension
7/16"-14 Grade 8
Socket / Drive
5/8" Socket
Sequence: Star pattern in 2 stages: initial seat to 35 N·m (26 ft-lb), then final 81 N·m (60 ft-lb).
CRITICAL CAUTION: Factory workshop manuals mandate replacing pulley bolts every time they are removed. Never reuse stretched pulley bolts.
Chassis & SuspensionNone (Clean Dry Threads / Light Grease on Shaft)
Front Wheel Axle Spindle / Bolt
Tightening Torque
88 N·m
64.9 ft-lb
Thread Dimension
3/4"-16
Socket / Drive
15/16" Socket
Sequence: Torque axle bolt first while pinch bolts remain loose. Pump front forks 3–4 times before torquing pinch bolts.
CRITICAL CAUTION: Torquing pinch bolts before axle nut causes fork binding, stiction, and severe front brake shudder.
Chassis & SuspensionNone (Clean Dry)
Front Axle Fork Bottom Pinch Bolts
Tightening Torque
23 N·m
17 ft-lb
Thread Dimension
M8 × 1.25
Socket / Drive
6 mm Allen / 12 mm Socket
Sequence: Dual pinch forks: alternate tightening between inner and outer bolt 3 times until wrench clicks on both without moving.
CRITICAL CAUTION: Tightening one bolt relaxes the adjacent bolt. Failure to alternate causes pinch bolts to work loose under road vibration.
Chassis & SuspensionNone (Factory Locknut / Cotter Pin)
Rear Axle Castle / Flange Nut
Tightening Torque
135 N·m
99.6 ft-lb
Thread Dimension
1"-14 / M25
Socket / Drive
36 mm Socket
Sequence: Push wheel forward against adjusters while torquing. Insert fresh cotter pin or R-clip through castle slot.
CRITICAL CAUTION: Under-torquing allows axle cocking, throwing wheel out of alignment; over-torquing crushes wheel bearing spacer tubes.
Chassis & SuspensionMedium Strength (Blue 242/243)
Rear Shock Upper & Lower Mount Bolts
Tightening Torque
44 N·m
32.5 ft-lb
Thread Dimension
M10 × 1.25
Socket / Drive
14 mm / 17 mm Socket
Sequence: Torque bolts with rear suspension loaded at static ride height (wheel on ground), not at full hanging droop.
CRITICAL CAUTION: Torquing shock eyelet rubber/spherical bushings at full droop locks preload twist into bushings, causing premature bushing tear.
Chassis & SuspensionNone (Clean Dry)
Swingarm Pivot Shaft Nut
Tightening Torque
65 N·m
47.9 ft-lb
Thread Dimension
M18 × 1.5
Socket / Drive
22 mm / 27 mm Socket
Sequence: Set swingarm pivot thrust collar clearance with spanner tool before torquing central through-shaft nut.
CRITICAL CAUTION: Incorrect pivot preload crushes needle bearings or induces lateral swingarm wobble and high-speed tank-slappers.
Cockpit & SteeringNone (Clean Dry)
Upper Triple Clamp (Fork Bridge) Pinch Bolts
Tightening Torque
26 N·m
19.2 ft-lb
Thread Dimension
M8 × 1.25
Socket / Drive
6 mm Allen / 12 mm Socket
Sequence: Verify fork tube height / stanchion protrusion above top bridge matches factory spec with vernier caliper before tightening.
CRITICAL CAUTION: Uneven fork tube heights alter chassis steering geometry, trail, and induce high-speed head-shake.
Cockpit & SteeringNone (Clean Dry)
Lower Triple Clamp Pinch Bolts
Tightening Torque
23 N·m
17 ft-lb
Thread Dimension
M8 × 1.25
Socket / Drive
6 mm Allen / 12 mm Socket
Sequence: Alternate between upper and lower bolt on each side 3 times to achieve uniform clamping without localized tube deformation.
CRITICAL CAUTION: CRITICAL: Overtightening lower clamp pinches the outer fork slider oval, locking fork bushings and causing severe suspension stiction.
Cockpit & SteeringNone (Clean Dry)
Handlebar Riser Clamps / Clip-on Clamps
Tightening Torque
24 N·m
17.7 ft-lb
Thread Dimension
5/16"-18
Socket / Drive
1/4" Allen
Sequence: MANDATORY ZERO-GAP RULE: Tighten front bolts until clamp casting touches bottom casting with zero gap; then torque rear bolts to spec.
CRITICAL CAUTION: Leaving a gap at the front bolts allows handlebars to slip under sudden hard emergency braking.
Cockpit & SteeringNone (Clean Dry)
Steering Stem Head Nut
Tightening Torque
110 N·m
81.1 ft-lb
Thread Dimension
M28 × 1.0
Socket / Drive
30 mm / 36 mm Socket
Sequence: Ensure upper triple clamp pinch bolts are loose when torquing stem nut to prevent binding the steering bearings.
CRITICAL CAUTION: This nut clamps the top bridge; steering head bearing preload is adjusted separately via the lower castle spanner ring.
Cockpit & SteeringNone (Clean Dry)
Front Brake Master Cylinder Clamp Bolts
Tightening Torque
10 N·m
89 in-lb
Thread Dimension
M6 × 1.0
Socket / Drive
8 mm Hex / 5 mm Allen
Sequence: Align "UP" arrow mark on split clamp upward. Tighten upper bolt first until clamp seats flush; then torque lower bolt to 10 N·m.
CRITICAL CAUTION: Tightening bottom bolt first pinches the reservoir casting unevenly, cracking master cylinder clamp ears.
Brakes & HydraulicsMedium Strength (Blue 242/243) / Factory Micro-Encapsulated
Front Brake Caliper Mount Bolts
Tightening Torque
45 N·m
33.2 ft-lb
Thread Dimension
3/8"-16 High Tensile
Socket / Drive
10 mm 12-Point Socket
Sequence: Radial calipers: tighten upper and lower bolts in two equal stages (20 N·m, then final spec).
CRITICAL CAUTION: Radial caliper mounting threads tap directly into aluminum fork bottoms. Never use pneumatic/electric impact guns.
Brakes & HydraulicsMedium Strength (Blue 242/243)
Rear Brake Caliper Mount / Bracket Bolts
Tightening Torque
23 N·m
17 ft-lb
Thread Dimension
M8 × 1.25
Socket / Drive
12 mm Socket / 6 mm Allen
Sequence: Ensure caliper bracket sliding torque arm slot engages swingarm tab cleanly before tightening.
CRITICAL CAUTION: Unengaged bracket tabs allow rear caliper to rotate with disc during braking, shearing brake lines.
Brakes & HydraulicsMedium Strength (Blue 242/243 Mandatory)
Front Brake Disc Rotor Bolts
Tightening Torque
24 N·m
17.7 ft-lb
Thread Dimension
M8 × 1.25 Low-Profile Shoulder
Socket / Drive
6 mm Allen / T40 Torx
Sequence: Clean wheel hub female threads with solvent; apply 2 drops of Blue 243. Tighten in criss-cross star pattern across 2 stages.
CRITICAL CAUTION: A loose brake rotor bolt can back out and impact the front fork leg, instantly locking the front wheel.
Brakes & HydraulicsMedium Strength (Blue 242/243 Mandatory)
Rear Brake Disc Rotor Bolts
Tightening Torque
47 N·m
34.7 ft-lb
Thread Dimension
M8 × 1.25 / M10 × 1.25
Socket / Drive
6 mm Allen / T40 Torx
Sequence: Criss-cross star pattern. Ensure disc sits 100% flat against wheel hub register with zero trapped debris.
CRITICAL CAUTION: Trapped dirt under rotor mounting flange causes severe brake pedal pulsation and lateral rotor runout.
Brakes & HydraulicsNone (Clean Dry with Fresh Copper Washers)
Hydraulic Brake Line Banjo Bolts
Tightening Torque
30 N·m
22.1 ft-lb
Thread Dimension
3/8"-24 / 7/16"-24
Socket / Drive
12 mm / 14 mm Hex Socket
Sequence: Always replace the two copper/aluminum crush washers per banjo joint. Never reuse crushed washers.
CRITICAL CAUTION: Over-torquing shears the cross-drilled fluid passage inside the banjo bolt, destroying the caliper casting.
Brakes & HydraulicsNone (Clean Dry)
Caliper Hydraulic Bleed Screws
Tightening Torque
6 N·m
53 in-lb
Thread Dimension
M7 × 1.0 / M8 × 1.25
Socket / Drive
8 mm / 10 mm Line Wrench
Sequence: Use 6-point flare-nut / line wrench to prevent rounding soft hex. Snug firmly until seated against conical seat.
CRITICAL CAUTION: Overtightening distorts the internal conical sealing point, causing persistent hydraulic fluid weeping.
Four Essential Workshop Tightening Protocols
1. Lower Triple Clamp Stiction Rule
Lower triple clamp pinch bolts must NEVER be torqued past factory spec (18–23 N·m). Overtightening pinches the outer fork slider oval, crushing internal bushings against the chrome stanchion and causing severe suspension stiction and premature seal failure.
2. Handlebar Clamp Zero-Gap Rule
Always tighten the front two clamp bolts until the upper clamp touches the bottom riser with ZERO clearance. Then torque the rear two bolts to spec. Leaving an equal gap front and rear allows handlebars to slip forward under sudden emergency braking.
3. Front Axle Bounce & Alignment
Torque front axle spindle nut first while pinch bolts are loose. Pump front forks up and down vigorously 3–4 times with front brake applied. This allows the right fork bottom to center itself freely along the axle spindle before torquing pinch bolts.
4. Star Pattern & Criss-Cross Torque
Always torque opposed bolts across a circular pattern in 2 progressive stages (50% torque stage 1, 100% final stage). Essential on brake disc rotors, engine case covers, and clutch pressure plates to prevent warping aluminum mating faces.
Metric Bolt Strength Grade & Tensile Markings Guide
Grade 8.8
Standard High Tensile (800 MPa)
Yield strength: 640 MPa. Used on footpeg brackets, fairing subframes, radiator brackets, and standard chassis mounts. Head stamped "8.8".
Grade 10.9
Extra High Tensile (1,040 MPa)
Yield strength: 940 MPa. Mandatory on front/rear brake caliper mounts, suspension linkages, and engine hanger bolts. Head stamped "10.9".
Grade 12.9
Ultra High Tensile (1,220 MPa)
Yield strength: 1,100 MPa. Extreme strength alloy steel used on cylinder head studs, crankcase through-bolts, and countershaft sprocket studs. Head stamped "12.9".
Stainless A2-70 / A4-80
Galling Hazard in Aluminum
Stainless steel galls into aluminum engine cases, seizing permanently. Never replace structural chassis or brake bolts with cosmetic hardware store stainless.
3-Phase Charging System & Battery Diagnostic Flowchart
Yuasa & OEM StandardsMultimeter troubleshooting protocols, cold cranking amps (CCA) ratings, 3-phase stator AC outputs, and regulator-rectifier health verification.
OEM Battery Code
YTX20HL-BS (VRLA / Heavy-Duty High-CCA AGM)
Cold Cranking Rating
310 CCA
Capacity (10HR Rate)
18 Ah (12V)
Regulated Output Spec
14.0 - 14.6 V DC
Key-OFF Parasitic Limit
< 2.0 mA (Security system armed)
V DC
Multimeter Test Diagnosis
Enter your multimeter terminal reading on the left to view instant diagnostic interpretations and recommended workshop actions.
OEM Factory AGM BatteryExact OEM Fit
Yuasa YTX20HL-BS High Performance AGM Battery
Dimensions: 175 L × 87 W × 155 H mm • Weight: 13.9 lbs (6.3 kg). Pre-filled absorbed glass mat technology engineered for heavy vibration resistance.
Lithium LiFePO4 UpgradeUp to 70% Lighter
Antigravity ATX-20 Re-Start (680 CCA / 3.8 lbs)
Features built-in RE-START jump starting reserve. Never stranded by dead lights: press the restart button on the top terminal to crank the motorcycle without jumper cables.
Smart Maintainer SpecBattery Life Extension
12V AGM / Float 1.5A
Standard Charge Rate: 1.8A (Max 3.5A). Automated desulfation & float maintenance ensures full capacity retention during off-season winter storage.
Recommended Parts: Yuasa YTX20HL-BS High Performance AGM Battery • OptiMate 4 Quad Program 1.0A Smart Battery Tender / Charger
CIRCUIT HEALTH DECKMain: 50A Maxi-FuseSpec: < 3.5 mA Quiescent
FUSE BOX, RELAY ASSIGNMENTS & PARASITIC DRAIN ISOLATOR
Fuse & Relay Location: Main fuse / BCM located behind left side cover; Main 40A/50A Maxi-Fuse mounted in dedicated holder adjacent to battery tray.
Select Fuse to Inspect Circuits & Failure SymptomsFormat: Maxi Blade (MAX) + Micro/Mini Blade
15A
SLOT: BATTERY
Constant Battery Feed
Downstream Protected Components:
BCM Keep-Alive MemorySpeedometer ClockSecurity Siren Module
Mechanic Diagnostic: Symptoms If Blown
Security system faults; odometer clock resets on shutdown.
Suspension Hydraulics, Fork Fluids & Interactive Sag Tuner
Showa • KYB • WP StandardsOEM hydraulic capacities, air-gap measurement standards, clicker baselines, and mathematical rider sag tuning.
Fork Architecture
Inverted USD Single-Cartridge (43mm Showa SDBV)
Oil Volume Per Leg
510 ml (17.2 US fl oz) per leg
OEM Fluid Specification
Harley-Davidson Type E / Heavy Fork Oil
Air-Gap Spec (Oil Level)
115 mm (4.53 in) compressed, spring removed
Fork Seal Dimensions
43 x 54 x 11 mm
Total Suspension Travel
Front: 130 mm • Rear: 112 mm
Target Rider Sag: 34 - 40 mm (26 - 31% of 130 mm travel)
Front Preload Baseline
Non-adjustable inverted cartridge
Rebound Damping Baseline
Showa Dual Bending Valve cartridge
Compression Damping Baseline
Showa Dual Bending Valve cartridge
Target Free Sag (Unladen)
20 - 25 mm
Enter 3-Point Sag Measurements (mm)
Suspension Sag Diagnosis & Geometry Status
Enter your extended, static, and rider measurements on the left (or select a preset) to compute exact sag percentages and spring preload recommendations.
Factory Fluid StandardDirect Spec
Maxima V-Twin Fork Oil Type E (1 Liter)
Formulated with anti-foam agents and shear-stable viscosity index improvers to prevent damping fade under aggressive riding heat.
Fork & Dust Seal KitExact Stanchion Fit
All Balls Racing 43mm Fork & Dust Seal Kit
Features directional triple-lip rubber seal profile and external garter springs engineered to withstand heavy stanchion flex without weeping.
Air-Gap Tuning PhysicsBottoming Control
115 mm (4.53 in) compressed, spring removed
Trapped air column acts as a progressive spring in final 30% of stroke. Adding +5mm oil increases bottoming resistance without stiffening small bump compliance.
Recommended Maintenance Parts: Maxima V-Twin Fork Oil Type E (1 Liter) • All Balls Racing 43mm Fork & Dust Seal Kit
BRAKING SYSTEM HYDRAULICS, WEAR LIMITS & CALIPER REBUILD MATRIX
Rotor Discard Limits (Tmin) • Caliper Piston Architecture • Pad Compounds • Hydraulic Bleed Specs
FACTORY CERTIFIED SPECIFICATIONS
Front Rotor Discs
300 mm × 5 mm
Discard Limit: 4.5 mm Tmin
Rear Rotor Disc
292 mm × 5.8 mm
Discard Limit: 5.1 mm Tmin
Caliper Architecture
Brembo 4-Piston Fixed Calipers (Dual Front Discs)
Rear: Brembo 2-Piston Floating Caliper
Hydraulic Fluid Standard
DOT 4 Synthetic Glycol
Dry BP ≥ 260°C • Wet BP ≥ 165°C
Caliper Bolt Torques (NM)
Mount: 38 N·m
Banjo: 27 N·m • Bleed: 8 N·m
Friction Material Lining
Sintered Metallic Heavy-Duty Touring Compound
Discard Pad at ≤ 1 mm
DIGITAL MICROMETER ROTOR WEAR DIAGNOSTIC GAUGE
Measure rotor friction ring with a pointed blade micrometer to verify safe thermal mass and discard limits
Enter Measured Disc Thickness (mm)
mm
Nominal New: 5.00 mm • Stamped Discard: 4.50 mm Tmin
Quick Benchmark Simulation Presets
Enter your micrometer rotor reading above or click a simulation preset to calculate remaining disc service life and discard safety status.
BRAKE PAD FRICTION COMPOUND & METALLURGY MATRIX
Compare OEM sintered metallic, organic carbon-ceramic, and racing compound friction dynamics
Compound Architecture
Double-H (HH) Sintered Metallic Compound
Friction Rating & Thermal Operating Envelope
HH Rated (μ ≥ 0.55 across cold and hot temperature zones)
0°C – 650°C (32°F – 1,200°F) • Exceptional High-Temp Fade Resistance
Lever Modulation & Initial Cold Bite
Sharp, aggressive initial bite with linear lever feel and minimal thermal hysteresis under repeated heavy slowdowns.
Rotor Wear Index & Wet Weather Recovery
Moderate to high rotor abrasive index. Requires hardened stainless steel rotors; not compatible with cast iron discs. • Superior wet recovery. Metallic sintered composition cuts cleanly through surface water film without delaying pad response.
Application & Recommended Riding Profile
Recommended for modern high-performance street motorcycles, spirited canyon riding, two-up touring, and occasional trackdays.
Hydraulic Fluid Bleeding & Caliper Overhaul Protocol
Hygroscopic Moisture Curve
Glycol brake fluid absorbs 2%–3% atmospheric water annually. Over 24 months, boiling point collapses from 260°C (500°F) to below 165°C (329°F), risking sudden vapor-lock brake loss. Flush fluid every 2 years.
Piston Seal Rollback Function
Caliper square-profile rubber seals flex under pressure to retract pistons ~0.15 mm when pressure drops. Hardened or dirty seals prevent rollback, causing continuous pad drag, glazed rotors, and fuel mileage loss.
Bleeder Torque & Sequence
Bleed master cylinder first, then furthest caliper, then nearest caliper. Tighten bleeder nipples to strictly 8 N·m. Over-tightening permanently shears threads in aluminum calipers.
Direct-Fit Braking Components & Hydraulic Fluids
Authentic double-H sintered pads, replacement floating rotors, and high-temp racing brake fluid
IGNITION ENGINEERING, HEAT-RANGES & COMBUSTION DIAGNOSTICS
OEM Spark Plugs • Heat-Range Dissipation • Coil Resistance • Visual Combustion Reading Matrix
FACTORY CERTIFIED SPECIFICATIONS
Factory Standard Plug
Harley-Davidson 6R10 / NGK CPR8EB-9
4 Plugs Total (Milwaukee-Eight 114: Dual-Spark Heads)
Electrode Spark Gap
0.8 - 0.9 mm (0.031 - 0.035 in)
M10 x 1.25 • 19 mm Reach
Hex Drive & Socket Spec
16 mm (5/8 in)
Use magnetic rubber-insert thin socket
Tightening Torque (NM)
15 N·m
1/2 turn after finger seat (crush washer)
Stick Coil Resistances
Pri: 0.5 - 0.7 Ω at 20°C
Sec: 6.0 - 8.0 kΩ at 20°C
Service & Replacement
Inspect: 5,000 miles (8,000 km)
Replace: 10,000 miles (16,000 km)
SPARK PLUG HEAT-RANGE & METALLURGY SELECTOR
Compare OEM standard, fine-wire precious metals, and ambient/duty cycle thermal dissipation paths
Verified Part Specification
Harley-Davidson 6R10 / NGK CPR8EB-9
Metallurgy & Center Tip Architecture
Copper Core / Solid Nickel Alloy Ground Electrode
Thermal Dissipation Path & Physics
Standard OEM factory thermal dissipation rate. Calibrated to stabilize ceramic nose temperature between 500°C–800°C across mixed street, highway, and mountain riding.
Operating Application Envelope
Stock engines, factory ECU mapping, general commuting, and standard touring. Recommended for all baseline maintenance schedules.
Ignitability & Coil Voltage Demand
Standard spark kernel size. Standard secondary coil demand (~15–20 kV). Solid copper core ensures rapid heat conduction away from tip.
SPARK PLUG READING & COMBUSTION DIAGNOSTICS ANALYZER
Interactive visual diagnosis: Match your ceramic insulator tip and electrodes to detect AFR, timing, oil intrusion, and thermal overload
Normal Clean — Optimal Combustion Equilibrium
OPTIMAL COMBUSTIONThermal Operating Range: 500°C – 800°C (932°F – 1,472°F) • Self-Cleaning Pyrolysis Window
Visual Insulator & Electrode Profile
Ceramic insulator nose is light grayish-tan, beige, or light brown. Firing tip and electrodes are dry with minimal combustion deposits. Ground electrode edges remain crisp without rounding or erosion.
Multimeter Electrical Resistance Test
Insulation Resistance > 10 MΩ (Infinite DC resistance between center terminal and steel shell). Dielectric barrier is pristine; zero spark leakage to cylinder head ground.
Probable Root Causes
- Optimal air/fuel ratio across all throttle positions (stoichiometric 14.7:1 cruise, 12.8:1–13.2:1 power enrichment)
- Correct spark plug heat range precisely matched to engine displacement and cooling efficiency
- Ignition timing and coil dwell saturation within factory parameters
- Healthy piston rings and valve guide seals with minimal oil blow-by
Prescribed Workshop Remediation Action
No mechanical intervention required. Inspect gap with wire-style feeler gauge and reinstall to factory torque specification.
Coil-on-Plug (COP) / Stick Coil Multimeter Bench Testing Protocol
Step 1 • Primary Circuit
Set DMM to lowest Ω range. Probe between Terminal 1 (+12V switched) and Terminal 2 (ECU trigger pin). Normal reading: 0.5 - 0.7 Ω at 20°C at 20°C.
Step 2 • Secondary Circuit
Set DMM to kΩ range. Probe between Terminal 1 and the high-voltage spark plug spring terminal inside the boot. Factory spec: 6.0 - 8.0 kΩ at 20°C at 20°C.
Step 3 • Dielectric Boot Inspection
Flex silicone boot under bright light. Check for pinholes, white powdery dielectric breakdown tracks, or hardened silicone causing high-voltage flashover to the cylinder head spark plug tube.
Direct-Fit Ignition Components & Workshop Sockets
Authentic laser iridium plugs, thin-wall magnetic sockets, and OEM replacement stick coils
Harley Davidson Diagnostic Fault Codes & Multimeter Bench Testing
FI & OBD2 DecoderAuthentic factory ECU fault codes, sensor resistance specifications, and harness pinout troubleshooting.
Code P0105Manifold Absolute Pressure (MAP)
MAP sensor electrical circuit malfunction / range error.
Test: Verify 5.0V VRef and 2.5-3.0V signal key-on engine-off.
Code P0115Engine Coolant Temp (ECT)
ECT sensor circuit open, short, or out of plausible range.
Test: Measure NTC thermistor: ~2.5 kΩ at 20°C, 300 Ω at 80°C.
Code P0335Crankshaft Position Sensor (CKP)
CKP sensor electrical circuit or missing pulse teeth.
Test: Measure VR magnetic pickup coil resistance (typically 200-600 Ω).
Looking for other error codes, sensor pinouts, or OBD2/Euro 5 codes?
Factory Service Schedule
Scheduled Maintenance Punch-List & Service Estimator
Select a factory interval milestone or enter your current odometer reading to preview scheduled workshop tasks for the 2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight).
ODOMETER:MILES
FACTORY INTERVALS:
Workshop Tablet Punch-List Progress0 of 9 Tasks Signed Off (0%)
Fluids & Engine
UPCOMING SOON0.8 HR BOOK
Engine Oil & Filter Element Replacement
4.70 L (5.00 US qt) (20W-50)
- Drain Plug Torque: 43 N·m (31.7 ft-lb)
- Always install a fresh OEM aluminum crush washer (M12/M14)
- Pre-lube new filter O-ring with fresh engine oil prior to spin-on install
- Warm engine to operating temperature before draining for complete sediment evacuation
TOOLS: 17mm Hex Socket + 65mm 14-Flute Filter Cup
PARTS/FLUIDS: 20W-50 Full Synthetic 4T Oil + Filter + Crush Washer
Ignition & Air
INSPECT / OK1.2 HR BOOK
Spark Plug Inspection / Direct-Replacement
Harley 6R10 / NGK CPR7EA-9 (Gap: 0.8 - 0.9 mm)
- Tightening Torque: 13 N·m (9.6 ft-lb)
- Hand-thread plug completely down to cylinder head seat before applying torque wrench
- Inspect electrode coloration for stoichiometric AFR balance (tan/light grey)
- Apply thin film of dielectric grease to interior of coil-on-plug boots
TOOLS: 14mm / 16mm Thin-Wall Spark Plug Socket + Feeler Gauge
PARTS/FLUIDS: Harley 6R10 / NGK CPR7EA-9 + Dielectric Silicone Grease
Hydraulics & Brakes
INSPECT / OK1 HR BOOK
Brake Fluid Full Hydraulic Flush & De-Aeration
DOT 4 Flush (Front Dual + Rear)
- Bleeder Nipple Torque: 8 N·m (Do not over-torque aluminum threads)
- Hygroscopic degradation: brake fluid absorbs atmospheric moisture; discard if moisture > 3.7%
- Flush master cylinder reservoir completely before cycling ABS hydraulic modulator
- Wash painted/plastic bodywork immediately with clean water if fluid contact occurs
TOOLS: 8mm / 10mm Bleeder Box Wrench + Clear Bleeder Hose + Catch Bottle
PARTS/FLUIDS: DOT 4 High-Performance Glycol Ether Brake Fluid + Isopropyl Alcohol
Hydraulics & Brakes
DUE NOW0.4 HR BOOK
Rotor Thickness & Pad Friction Lining Inspection
Front Min: 4.5 mm | Rear Min: 5.1 mm
- Front Caliper Mounting Torque: 38 N·m
- Minimum friction material thickness: 1.0 mm (excluding steel backing plate)
- Check rotor surface for deep grooving, heat bluing, or radial thermal stress cracks
- Verify caliper slide pins are free of corrosion and lubricated with silicone grease
TOOLS: Digital Micrometer (0-25mm) + Vernier Caliper + Torx T50 / 12mm Socket
PARTS/FLUIDS: Brake Contact Degreaser + High-Temp Synthetic Caliper Pin Grease
Drivetrain
DUE NOW0.4 HR BOOK
Drive Belt Deflection & Cog Inspection
Belt Deflection 5-7 mm @ 10 lbs
- Check drive belt deflection using spring-loaded belt tension tester
- Inspect cog teeth for stone chips, cord fraying, or uneven tooth wear
- Verify rear wheel alignment hash marks are matched evenly on both swingarm sides
TOOLS: Rear Axle Socket (27mm/32mm) + Alignment Gauge + Torque Wrench
PARTS/FLUIDS: O-Ring Safe Chain Degreaser + Synthetic Chain Lube
Ignition & Air
INSPECT / OK0.5 HR BOOK
Engine Air Intake Filter Element Service
OEM High-Efficiency Paper Element / Multi-Layer Cotton
- Remove fuel tank / side fairing panels to access airbox cover screws
- Inspect airbox lower cavity and drain hose for blowby oil condensation
- Do not blow compressed air through viscous paper filter elements (destroys filtration matrix)
- Verify airbox lid seal is properly seated to prevent unfiltered dust bypass
TOOLS: 4mm / 5mm Hex Allen Wrenches + JIS #2 Screwdriver
PARTS/FLUIDS: Replacement OEM Air Filter Element + Clean Microfiber Cloth
Fluids & Engine
INSPECT / OK1 HR BOOK
Engine Cooling System Flush & Radiator De-Aeration
Silicate & Borate-Free HOAT 50:50 Premix (-37°C / -35°F)
- Only open radiator cap when engine is completely cold (ambient temperature)
- Drain coolant from water pump drain bolt and radiator lower hose connection
- Flush cooling circuit with distilled water before filling with fresh 50:50 HOAT coolant
- Cycle engine until radiator fan activates, then burp cooling jacket to eliminate air pockets
TOOLS: 8mm / 10mm Drain Bolt Socket + Catch Pan + Radiator Cap Tester
PARTS/FLUIDS: Silicate-Free Long-Life Motorcycle Coolant (50:50 Distilled Water Premix)
Valvetrain
INSPECT / OK3.8 HR BOOK
Valve Clearance Inspection & Camshaft Timing Audit
Intake: 0.12 - 0.20 mm | Exhaust: 0.22 - 0.30 mm
- Strict requirement: engine must be cold (temperature <= 35°C / 95°F) for accurate readings
- Rotate crankshaft to compression Top Dead Center (TDC) for each cylinder firing order
- Shim Diameter: 9.48 mm
- Replace valve cover gasket and spark plug well O-rings upon reassembly
TOOLS: Angled Blade Feeler Gauges (0.04-0.35mm) + Digital Micrometer + Magnet Pen
PARTS/FLUIDS: Valve Shim Assortment Kit + OEM Valve Cover Gasket + ThreeBond Liquid Gasket
Chassis & Safety
DUE NOW0.5 HR BOOK
Chassis, Axle & Safety Critical Fastener Audit
Front Axle: 91 N·m | Rear Axle: 150 N·m
- Front Axle Pinch Bolts: 23 N·m (Tighten alternately twice)
- Front Caliper Mounting Bolts: 38 N·m
- Check triple clamp pinch bolts, handlebar clamps, and footpeg brackets
- Inspect steering head bearings for notchiness or play at center-detent
TOOLS: Calibrated 3/8" & 1/2" Click-Type Torque Wrenches + Metric Sockets
PARTS/FLUIDS: Blue Medium-Strength Threadlocker (Loctite 243)
Tool Pre-Flight
Calibrated Instruments & Drive SpecificationsWorkshop Tool & Chemical Pre-Flight Card
Sockets, Hex Bits & Wrenches
17mm Metric Hex Socket
Engine oil drain plug removal & torquing
65mm 14-Flute Oil Filter Cup Wrench
Spin-on oil filter removal & install (3/8" drive)
14mm / 16mm Thin-Wall Spark Plug Socket
Spark plug removal & installation
12mm / 14mm Radial Caliper Socket
Brake caliper mounting bolts
8mm / 10mm Bleeder Box Wrench
Hydraulic caliper bleed nipple opening
Front & Rear Axle Sockets (19mm - 32mm)
Wheel axle spindle nuts & chain adjustment
Calibrated Precision Instruments
1/4" Drive Torque Wrench (5 - 25 N·m)
Bleed valves, spark plugs, casing screws
1/2" Drive Torque Wrench (30 - 160 N·m)
Axle nuts, caliper bolts, drain plugs
Angled Blade Feeler Gauge Set (0.04 - 0.35 mm)
Valve clearances & spark plug electrode gap
Digital Rotor Micrometer (0 - 25 mm)
Brake disc minimum discard thickness verification
Workshop Chemicals & Consumables
Blue Medium Threadlocker (Loctite 243)
Brake caliper, rotor, and footpeg fasteners
High-Temp Anti-Seize Paste
Spark plug threads & axle spindle coating
DOT 4 Synthetic Brake Fluid
Hydraulic brake & clutch system flushing
Synthetic O-Ring Chain Degreaser & Lube
Drive chain cleaning & roller lubrication
New OEM Aluminum Crush Washers (M12 / M14)
Oil drain plug sealing (single-use)
Dealership Flat-Rate Labor vs. DIY Workshop Cost Estimator
Compare authorized dealership retail service invoicing against performing scheduled maintenance in your private shop.
DEALER LABOR RATE:$150/hr
Estimated Dealership Retail Invoice
Flat-Rate Labor (1.3 hrs @ $150/hr):$195.00
OEM Fluids & Parts (35% Dealer Markup):$61.00
Shop Supplies & Waste Disposal Fee:$25.00
Dealership Quote Subtotal:$281.00
DIY Private Workshop Investment
Factory Fluids & Replacement Filters:$45.00
Workshop Mechanical Labor:$0.00 (Owner Performed)
Environmental Disposal Fee:$0.00 (Free Auto Recycling)
Total DIY Investment:$45.00
You Save $236.00 (84%) by Servicing in Your Workshop
Includes matched OEM fluid capacities, filter, and authentic factory torque specifications.
1-Click Factory Service KitOEM Spec Fluid Capacities Matched
Workshop Maintenance Kit & Factory Fluids
Authentic factory-grade motor oil, oil filter, and high-temp brake fluid matched precisely to 2024 Harley Davidson Low Rider S (FXLRS Milwaukee-Eight) capacities.
Full Kit Subtotal
$65.34
Matches factory 20W-50 spec (Oil spec: 4.70 L (5.00 US qt))
Item Price
$47.80($11.95 ea)
Premium OEM-spec replacement with 17mm hex nut
Item Price
$11.99
DOT 4 Synthetic Formula
EBC High-Performance DOT 4 Synthetic Brake Fluid
8.8 oz (250 ml) Workshop Bottle
Meets & exceeds factory DOT 4 specifications
Item Price
$5.55
Factory OEM Spark Plug Spec
Harley 6R10 / NGK CPR7EA-9
Gap: 0.8 - 0.9 mm (0.031 - 0.035 in)
Inspection milestone: 10,000 miles (16,000 km). Exact factory part specification.
Authentic OEM Reference
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