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Yangtze MotoExportExport & Sourcing · Chongqing

Platform manual

NC450-class 450cc single (enduro, rally, ADV)

The NC450 family is the liquid-cooled DOHC 4-valve 450 single that powers most Chongqing-built 450 enduros, rally and adventure bikes. It is derived from a proven Japanese-style architecture, uses EFI on all current versions and is the best-supported big single in China: parts, tuning knowledge and mechanics are everywhere.

Read this first. Every value on this page is typical or indicative for the NC450-class 450cc single 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)

TypeSingle cylinder, 4-stroke, liquid-cooled, DOHC, 4 valves (typical for the platform; confirm on the unit’s spec sheet)
Displacement449.5 cc
Bore × stroke94.0 × 64.8 mm
Compression ratio≈ 11.5–12.0 : 1
Fuel systemEFI, 42–44 mm throttle body, typically Delphi / Bosch-type ECU
Rated output≈ 30–34 kW (40–46 hp) @ 8,500–9,000 rpm; ≈ 40–45 Nm @ 6,500–7,000 rpm depending on tune
StartingElectric (some enduro versions add kick start)
Gearbox6-speed constant mesh, wet multi-plate clutch, chain final drive (520 pitch)
CoolingLiquid, twin radiators on rally/enduro, thermostat + electric fan
Fuel92 RON (95 recommended for sustained high load), typical tank 8–14 L (enduro) / 16–22 L (rally)

Catalog models on this platform: 450cc Rally / ADV (NC450-class engine), 450cc Enduro (NC450-class engine). Model-specific figures are on each model page.

Fluids & capacities

Engine oilSAE 10W-40 or 10W-50, API SL+/JASO MA2 motorcycle oil; ≈ 1.3–1.6 L with filter change (typical)
Coolant50/50 ethylene-glycol motorcycle coolant; ≈ 1.1–1.4 L system
Brake fluidDOT 4 (front and rear)
Fork oilSAE 5W–10W fork oil; level per fork brand (KYB / FastAce / Yuan clones), typically 100–130 mm from top
Chain lubeO-ring-safe chain lubricant

Break-in

  1. 0–300 km: keep below ≈ 5,000 rpm, vary the throttle constantly, no full-throttle runs, no sustained speed above 80 km/h. Avoid long idling.
  2. 300–800 km: gradually raise the ceiling to ≈ 7,000 rpm; short bursts of higher load are fine, sustained high rpm is not.
  3. 800–1,000 km: normal riding, still avoid holding maximum rpm for long stretches.
  4. First service at 300–500 km: change engine oil and filter (this is where the assembly debris comes out), check valve clearance, re-torque spokes, axle nuts, sprocket bolts and engine mounts, adjust chain, check coolant level and all fasteners on plastics and racks.
  5. Second service at 1,000 km: oil again, check valve clearance if it was not done at the first service, re-check chain and brakes.

Why each rule exists →

Maintenance schedule

ItemFirstThen everyNotes
Engine oil300–500 kmEvery 2,500–3,000 km or 6 monthsEvery 1,500 km in dust or race use
Oil filter300–500 kmEvery oil change
Valve clearance500–1,000 kmEvery 5,000–6,000 kmTypical clearances: intake 0.10–0.15 mm, exhaust 0.20–0.25 mm — confirm in the manual
Air filter500 kmClean every 1,000 km, replace 5,000 kmAfter every ride in sand/dust
Spark plugInspect 5,000 km, replace 10,000 kmTypical: NGK CR8E/CR9E-type or equivalent
Chain & sprockets300 kmAdjust/lube every 500 km; replace as a set 15,000–20,000 kmSlack ≈ 35–45 mm on the sidestand (typical)
CoolantCheck level monthly; replace every 2 years
Brake fluidCheck level monthly; replace every 2 years
Brake padsInspect every 2,500 km; replace at 1.5 mm
Fork oil & sealsEvery 10,000–15,000 km or when leaking
Steering head & swingarm bearings1,000 km (re-torque)Grease/inspect every 10,000 km
Spokes300 kmCheck tension every 1,000 km (off-road use)
BatteryCheck charge every 3 months if stored; ≈ 12.6–12.8 V rested

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

Torque values (indicative)

Front axle nut≈ 60–80 Nm
Rear axle nut≈ 90–110 Nm
Rear sprocket bolts≈ 30–35 Nm
Front sprocket nut≈ 60–75 Nm (bend lock tab)
Brake caliper mounting bolts≈ 25–30 Nm
Brake disc bolts≈ 12–15 Nm (thread-lock)
Handlebar clamp bolts≈ 22–28 Nm
Triple clamp pinch bolts≈ 20–25 Nm (upper) / 25–30 Nm (lower)
Engine oil drain plug≈ 20–25 Nm
Oil filter cover≈ 10–12 Nm
Spark plug≈ 12–15 Nm
Engine mounting bolts≈ 40–55 Nm
Footpeg / subframe bolts≈ 25–35 Nm
NoteIndicative values for this class of machine. Use the value printed in the supplied manual if it differs.

Tire pressures

Enduro / trail (21" / 18")Off-road 0.9–1.1 bar (13–16 psi); road 1.6–1.8 bar front / 1.8–2.0 bar rear
Rally / ADV (21" / 18" or 19" / 17")Road 1.9–2.1 bar front / 2.1–2.3 bar rear; sand 1.0–1.2 bar
Tube typeMost units are tube-type; carry a 21" front tube, which also works in the rear in an emergency

Common issues

SymptomLikely causeFix
Will not start after unloading; starter clicks or is slowBattery discharged during 4–8 weeks of shipping (often shipped disconnected, sometimes partially charged).Charge with a smart charger at 1–2 A for 6–10 hours before first start. Do not jump-start from a car with the engine running. If the battery will not hold 12.5 V after charging, replace it (claimable within the first 30 days).
Starts, then stalls; rough idle; smells of stale fuelFactory test fuel has aged during transport, or the tank was drained and the injector rail is empty.Fill with fresh 92–95 RON, cycle the key 3–4 times to prime the pump (listen for the 2-second whine), then crank. Idle for 5 minutes with the throttle closed so the ECU relearns.
Fault lamp on; ECU error codeA sensor connector loosened in transit (TPS, oxygen sensor, coolant temperature) or a disconnected fuel-pump plug.Read the code: most Delphi-type ECUs blink the MIL when the diagnostic pin is bridged, or use a generic OBD-M / K-line reader (provided on request). Reseat every connector under the tank first; 80% of codes clear after this.
Engine overheats in slow riding; fan not runningAir lock in the cooling system, fan fuse pulled for shipping, or fan thermo-switch connector off.Bleed the system: loosen the bleed screw or top hose with the engine warm, top up. Check the fan fuse (usually 10–15 A) and that the fan runs when 12 V is applied directly. Normal fan-on temperature is ≈ 95–100 °C.
Chain slaps or jumps; noise from the rearChain set loose for crating or over-tight at assembly.Set slack to ≈ 35–45 mm at the tightest point with the bike on its stand; align using the swingarm marks; torque the axle.
Charging voltage low; battery drains overnightRegulator/rectifier connector corroded, or a parasitic drain from an aftermarket alarm/GPS fitted at the factory.Measure 13.8–14.5 V at 5,000 rpm across the battery. If lower, check the stator AC output (typically 20–70 V AC per phase, rising with rpm) and the regulator plug. Disconnect any tracker fitted and measure current draw (<10 mA is normal).
Oil weeping from the head cover or clutch cover after the first 500 kmGaskets settle during break-in; bolts loosen slightly.Re-torque the cover bolts in a cross pattern to ≈ 10–12 Nm. Persistent leaks: replace the gasket (in the spare-parts kit).
Hard gear engagement / false neutralsClutch cable stretch after break-in, or wrong oil (car oil with friction modifiers).Set 10–15 mm free play at the lever; use JASO MA2 motorcycle oil only.

Universal post-shipping checks →

Fast-moving parts (recommended per 10 units)

PartPer 10 unitsNote
Oil filter30
Air filter (foam or paper)20
Spark plug10
Front & rear brake pads (sets)10 each
Clutch cable / throttle cable5 / 5
Clutch & brake levers10 eachFirst things broken in a drop
Chain 520 (120 links) & sprocket set5 sets
Drive chain master link10
Inner tubes 21" & 18"10 / 10
Head-cover & clutch-cover gaskets5 / 5
Fork seals & dust seals5 pairs
Mirrors, indicators, hand guards5 / 10 / 5
Radiator fan, thermo-switch1 / 2
Fuel pump assembly1–2
Regulator/rectifier, starter relay1–2 / 2
Plastics set (shrouds, fenders)2 setsColour-matched, ordered with the bikes

How to identify and order parts →

Tools & safety

Workshop tools

  • Metric sockets 8–24 mm, 27 mm & 32 mm for axles
  • Torque wrench 5–60 Nm and 40–200 Nm
  • Feeler gauges 0.05–0.30 mm and valve-shim kit (7.48 mm shims typical)
  • Smart battery charger
  • Chain breaker/riveter (520)
  • Spoke wrench
  • Multimeter
  • Generic K-line / OBD-M diagnostic reader for Delphi-type ECUs

Safety notes

  • Never run the engine in a closed room; the fan will not keep it cool at idle for long.
  • Coolant is toxic and boils under pressure — open the radiator cap only when cold.
  • A bike shipped with the front wheel out has its brake caliper hanging free: do not squeeze the front lever before the wheel and disc are fitted.
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 NC450-class 450cc single models?

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

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