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Yangtze MotoExportExport & Sourcing · Chongqing

Platform manual

500cc parallel-twin (street, naked, mini-ADV)

The 471–500 cc DOHC 8-valve parallel twin is the most common Chinese mid-size engine, produced by several Chongqing and Zhejiang makers to a Honda-derived layout. Smooth, easy to service, EFI everywhere, ABS on most export variants. Same maintenance logic as any modern Japanese twin.

Read this first. Every value on this page is typical or indicative for the 500cc parallel-twin class, compiled for dealer workshops. Yangtze Moto Export is an export company, not the manufacturer. The owner’s and service manual supplied with each unit prevails wherever it differs; where a value is not printed in your manual, use these as a starting point and confirm by inspection.

Specifications (typical for the platform)

TypeParallel twin, 4-stroke, liquid-cooled, DOHC, 8 valves (typical; confirm on spec sheet)
Displacement471–500 cc
Bore × stroke67.0 × 66.8 mm (471 cc) or 69 × 66.8 mm (500 cc) — typical
Crank180° (most) or 360° balance-shaft designs
Compression ratio≈ 10.7–11.5 : 1
Fuel systemEFI, twin 32–36 mm throttle bodies, Bosch / Delphi ECU
Rated output≈ 33–37 kW (45–50 hp) @ 8,500 rpm; ≈ 42–46 Nm @ 6,500 rpm
Gearbox6-speed, wet multi-plate clutch (slipper on some), chain final drive 520
CoolingLiquid, single radiator + fan
Fuel92–95 RON; tank 14–18 L

Catalog models on this platform: 500cc Parallel-Twin Naked / Street. Model-specific figures are on each model page.

Fluids & capacities

Engine oilSAE 10W-40 JASO MA2; ≈ 2.4–2.8 L with filter (typical)
Coolant50/50 glycol; ≈ 1.6–2.0 L
Brake fluidDOT 4; ABS units need bleeding with ABS in mind (bleed calipers normally; ABS module rarely needs it)
Fork oilSAE 10W; USD forks per manual

Break-in

  1. 0–500 km: below ≈ 5,000 rpm, vary throttle, no sustained speed above 90 km/h.
  2. 500–1,000 km: raise to ≈ 7,000 rpm; brief higher loads acceptable.
  3. First service at 500–1,000 km: oil + filter, check valve clearance, chain, re-torque.

Why each rule exists →

Maintenance schedule

ItemFirstThen everyNotes
Engine oil & filter500–1,000 kmEvery 4,000–5,000 km or 6 months
Valve clearance1,000 kmEvery 8,000–12,000 kmShim-under-bucket; typical in 0.16 ± 0.03 mm, ex 0.25 ± 0.03 mm — confirm
Air filterInspect 5,000 km, replace 15,000 km
Spark plugs (2)Replace 12,000–15,000 kmCR8E-type or iridium equivalent
Chain & sprockets500 kmAdjust every 1,000 km; set at 20,000–25,000 km
CoolantEvery 2 years / 24,000 km
Brake fluidEvery 2 years
Brake padsInspect 5,000 km
Throttle-body sync1,000 kmEvery 12,000 kmUneven idle is the symptom

Halve intervals for dust, sand, taxi/cargo duty or track use.

Torque values (indicative)

Front axle≈ 60–70 Nm
Rear axle nut≈ 90–100 Nm
Rear sprocket nuts≈ 30–35 Nm
Caliper mounting≈ 28–32 Nm
Handlebar clamps≈ 22–26 Nm
Drain plug≈ 25–30 Nm
Oil filter (spin-on)≈ 17–20 Nm
Spark plugs≈ 12–14 Nm
NoteIndicative values for this class of machine. Use the value printed in the supplied manual if it differs.

Tire pressures

Street (17" / 17")2.25 bar front / 2.5 bar rear solo; +0.2 bar with passenger
Mini-ADV (19" / 17")2.2 bar front / 2.5 bar rear

Common issues

SymptomLikely causeFix
ABS warning stays on after assemblyWheel-speed sensor gap wrong after refitting the front wheel, or sensor plug off.Set the sensor-to-ring gap to ≈ 0.5–1.5 mm, reconnect, ride above 10 km/h — the lamp self-clears.
Uneven idle, one header cooler than the otherThrottle bodies out of sync or an injector plug loose.Check both injector connectors; sync with a vacuum gauge set at idle per manual.
Will not start after shippingFlat battery / stale fuel.Charge battery, fresh fuel, prime pump 3× with the key, crank.
Fan runs constantly / temperature gauge highAir in the cooling system after the factory drained it for crating (rare) or a bent radiator.Bleed and top up; check the radiator for transit damage and claim with photos if bent.
Clutch drag when coldOil viscosity / cable free play.10W-40 JASO MA2, 10–15 mm lever play; slipper-clutch units settle after 1,000 km.

Universal post-shipping checks →

Fast-moving parts (recommended per 10 units)

PartPer 10 unitsNote
Oil filter30
Spark plugs20
Brake pads front/rear10 / 10
Levers (clutch/brake)10 each
Mirrors & indicators5 / 10
Chain & sprocket set3
Air filter10
Wheel-speed sensor2
Regulator/rectifier1
Fairing/side panels2 sets

How to identify and order parts →

Tools & safety

Workshop tools

  • Metric sockets & hex keys
  • Torque wrenches
  • Feeler gauges + shim kit
  • Vacuum sync gauges
  • Battery charger
  • Diagnostic reader (Bosch/Delphi-compatible)

Safety notes

  • ABS models: never clamp brake lines; keep the battery connected while bleeding to avoid module faults.
  • Do not tow-start EFI bikes.
Missing a value your manual does not print? Send the VIN and the question: WhatsApp +1 646 235 7816. We answer within 48 hours and add the answer to this page.

Quoting 500cc parallel-twin models?

Every quote ships with this guide attached, so your mechanic knows the workload before you commit.

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