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Yangtze MotoExportExport & Sourcing · Chongqing

Something’s wrong

Troubleshooting

Ninety percent of post-shipping faults are a flat battery, stale fuel or a connector that let go on the sea. Start with the universal list, then go to your platform.

Universal: any platform, first week

SymptomLikely causeFix
Will not start after unloadingBattery discharged in transit; fuel tank empty or stale; kill switch off; sidestand/clutch interlock.Charge the battery fully (not a quick boost). Fresh fuel, prime the pump 3–4 key cycles. Kill switch to RUN, neutral, sidestand up. Then crank in 5-second bursts.
Starts, dies when the throttle opensInjector rail empty / fuel pump plug off; on carb bikes a blocked pilot jet.EFI: check the pump connector under the tank, listen for the 2-second whine at key-on. Carb: drain the bowl, clean the pilot jet.
Warning lamp on the dashA connector loosened in transit, or a system that needs a relearn (ABS, TPS, IMU).Reseat every connector under the tank and seat first. ABS clears after riding > 10 km/h. Read the code before replacing anything.
Battery flat again next morningParasitic drain from a tracker/alarm, or a charging fault.Measure draw with the key off (< 10 mA normal). Check 13.8–14.5 V across the battery at 5,000 rpm.
Something rattles / a bolt is missingCrating removes parts; hardware bag not fully used.Go through the torque list on the assembly page; count the hardware bag against the diagram.

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

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.

Specs, torque and parts for this platform →

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

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.

Specs, torque and parts for this platform →

250cc single (enduro / trail)

SymptomLikely causeFix
Carburettor model floods / idles badly after shippingStale fuel varnish in the pilot jet; float stuck.Drain the bowl, clean the pilot jet with carb cleaner and compressed air, fresh fuel.
Kick start only, no electric startFlat battery or starter relay connector.Charge; check the relay plug behind the side cover.
Ticking from the head increasing with rpmValve clearance opened up during break-in.Adjust at 500 km — takes 20 minutes with screw adjusters.
Oil in the airboxOverfilled crankcase (common at factory).Set the level to the dipstick/sight-glass mid-mark, not the top.

Specs, torque and parts for this platform →

250–300cc street single / twin (value big bikes)

SymptomLikely causeFix
TFT / LCD dash blankDash connector unplugged for crating; main fuse pulled.Check the fuse box under the seat and the dash multiplug behind the headlight.
Altitude (Andes) — rich running, black smokeBasic ECU maps without barometric correction on some cheap variants.Specify the EFI version with a MAP/baro sensor when ordering for markets above 2,000 m — we flag this at quote stage.
Won’t start after shippingBattery / stale fuel.Charge, fresh fuel, prime.
Rattle from fairing at speedFasteners loosened; plastic clips missing after crating.Re-check every fairing clip; extra clips are in the parts kit.

Specs, torque and parts for this platform →

400cc adventure single

SymptomLikely causeFix
Won’t start after shippingBattery / stale fuel / fuel pump plug.Charge, fresh fuel, check the pump connector under the tank.
Pannier racks looseCrated with racks off; bolts hand-tight.Torque rack bolts to ≈ 25 Nm with thread-lock.
Windscreen cracks at bolt holesOver-tightened during assembly.Use the rubber washers supplied; hand-tight + ¼ turn.

Specs, torque and parts for this platform →

650cc parallel-twin adventure tourer

SymptomLikely causeFix
TCS / ride-mode warning after battery reconnectThrottle grip needs relearn after power loss.Key on, do not touch the throttle for 10 s, then twist fully open/closed twice; ride to clear.
ABS lamp onWheel sensor gap after wheel refit.Set 0.5–1.5 mm, ride above 10 km/h.
Won’t start after shippingBattery / fuel.Charge; fresh fuel; prime.

Specs, torque and parts for this platform →

650cc V-twin cruiser

SymptomLikely causeFix
Belt squealBelt too tight after assembly or debris on the pulley.Set deflection per manual; clean pulleys.
Won’t start after shippingBattery / fuel.Charge; fresh fuel; prime.
Chrome pitting in coastal / Gulf climatesSalt air.Wax chrome on PDI; keep showroom units covered.

Specs, torque and parts for this platform →

CG / CB-type 150–200cc commuter & cargo

SymptomLikely causeFix
Won’t start; kick onlyFlat battery — small 12 V 5–7 Ah batteries lose charge fast in transit.Charge 4–6 h at 0.5–1 A; if below 12.4 V rested after charge, replace.
Hunting idle / stalls warm (carb)Pilot jet varnish; idle mixture screw disturbed.Clean jets; set the mixture screw 1½–2½ turns out, idle 1,400 ± 100 rpm.
Oil consumption after 5,000 km in taxi useAir filter neglected; dust wears rings.Enforce filter cleaning; sell filters with every service.
Rear brake drum squealDust / glazed shoes.Clean drum, light sand of shoes.
Headlight dim at idleAC lighting circuit on cheapest variants.Normal for AC-lighting bikes; DC-lighting or LED versions are available at order time.

Specs, torque and parts for this platform →

Electric motorcycle & scooter (2–5 kW class)

SymptomLikely causeFix
Dead on arrival — no dash, no powerBattery shipped at 30–50% and disconnected; main breaker / fuse off; key-switch plug off. Lithium packs with a BMS may “sleep” below a voltage threshold.Reconnect the pack, switch on the breaker, charge to 100%. If the BMS is in sleep, most wake when the charger is connected for 30–60 s; some need the charger connected before the discharge plug.
Charger LED stays red / green immediately, no chargingCharger polarity plug mismatch, wrong voltage charger, or BMS over-temperature lockout.Match charger voltage to pack (60 vs 72 V). Let the pack cool below 45 °C. If the charger shows green at once, the BMS is refusing — check the pack’s balance leads or claim.
Motor cuts out under load; dash shows error codeController over-current / hall sensor fault / phase wire loose after transit.Common controller codes: E1/E2 throttle, E3 controller, E4 motor hall, E5 brake switch, E6 under-voltage, E7 over-current, E8 motor phase (vendor-specific — the sheet in the parts kit lists yours). Reseat the three thick phase connectors and the five-pin hall plug; look for melted pins.
No throttle response, dash onBrake-lever switch stuck on (kill signal), sidestand switch, or throttle plug.Check both brake-lever switches with a meter; the controller will not drive while a brake switch is closed.
Range 30% below specLow tire pressure, cold weather, lead-acid pack sulphated during shipping, or rider in Sport mode.Pressures first; three full cycles to recover lead-acid; check mode. Lithium packs stored > 3 months below 20% may have lost capacity — claim with a capacity test.
Intermittent power, dash resetsLoose main negative or corroded Anderson connector.Clean, tighten, dielectric grease.
Regen / reverse not workingFeature disabled in controller parameters for the export market.Set via the controller app/programmer; we supply the parameter sheet.

Specs, torque and parts for this platform →

1000cc 4×4 UTV / side-by-side

SymptomLikely causeFix
Will not start; dash lights but no crankBattery low, brake pedal not pressed (interlock), gear not in P/N, seat-belt interlock on some models.Charge battery; press brake; confirm P/N; check seat-belt switch plug under the seat.
CVT belt slips / burning smellBelt not bedded, water in the CVT case, or oil contamination from a leaking seal.Bed the belt (50 km gentle); drain CVT housing via the drain plug at the bottom; clean pulleys with brake cleaner; replace belt if glazed.
Overheats at low speedRadiator mud-packed, fan fuse/relay, air lock.Pressure-wash the radiator from the engine side; check the 30 A fan fuse; bleed.
4WD will not engage / diff-lock light flashesActuator plug off, vacuum/electric actuator stuck, or engaging while rolling.Engage 4WD at standstill or rolling straight below 5 km/h; check the actuator connector on the front diff; cycle the switch 3× with the key on.
Clunk on take-offDriveshaft splines dry or U-joint play.Grease splines; check U-joints — claimable if loose on PDI.
Steering pulls / wandersToe out of spec after shipping tie-downs; tie-rod ends loose.Set toe to ≈ 0–3 mm toe-in; torque tie-rod nuts; check EPS connector if fitted.
Fault code on EFIConnector loosened in transit.Read via diagnostic port (kit available); reseat connectors under the hood and seat.

Specs, torque and parts for this platform →

300cc utility ATV

SymptomLikely causeFix
Won’t startBattery, brake-lever interlock, kill switch left off.Charge; hold the brake; kill switch to RUN.
Belt slips in water crossingsWater in CVT housing.Open the CVT drain plug; dry; check vent hose routing above the seat line.
Reverse hard to engageCable adjustment; shifter linkage loose after crating.Adjust the shift cable; torque linkage.
Pulls to one sideTire pressures uneven (very sensitive at 5 psi) or toe out.Equalise pressures with a low-range gauge; set toe.

Specs, torque and parts for this platform →

ZXMOTO inline-three (820RR) & inline-four (500RR / 500F)

SymptomLikely causeFix
Riding-mode / IMU warning after battery reconnectIMU and TPS need a relearn.Key on, bike upright and still for 10 s, then throttle relearn; ride to clear. Persisting codes: dealer tool.
Quickshifter not cuttingShift-rod sensor plug off or feature off in the menu.Reconnect; enable in the TFT menu.
Will not start after shippingBattery / stale fuel / immobiliser key not paired (some units ship with one key active).Charge; fresh fuel; use the key marked as primary; pair the second key per the manual.
ABS lampWheel-sensor gap after wheel refit.Set gap; ride above 10 km/h.

Specs, torque and parts for this platform →

Not solved in 30 minutes? Send VIN + photo + a 30-second video of the symptom to WhatsApp +1 646 235 7816. Reply within 48 hours; manufacturing defects go straight to a claim.

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