| Problem |
Description |
Solution |
| Engine won’t start |
No crank or power when trying to start. |
Check battery, ignition switch, kill switch, fuses, and starter relay. |
| Engine cranks but won’t start |
Engine turns over but does not fire. |
Check for spark, fuel flow, clean carburetor, inspect choke and compression. |
| No spark |
No ignition at spark plug. |
Test CDI, ignition coil, stator, spark plug, and all related wiring. |
| Weak or intermittent spark |
Spark plug fires inconsistently. |
Replace spark plug, test coil resistance, inspect connections and ground. |
| Hard starting (cold or hot) |
Requires multiple attempts to start or won’t start without throttle. |
Clean or rebuild carburetor, inspect choke/enricher, and verify fuel quality. |
| Engine stalls shortly after starting |
Engine runs briefly, then cuts off. |
Adjust idle screw, clean pilot jet, check for fuel/vacuum leaks. |
| Poor idle |
Engine idles rough, surges, or stalls at idle. |
Adjust idle and mixture screws, clean carburetor, check for vacuum leaks. |
| Loss of power |
Sluggish response or poor acceleration. |
Check air filter, clean carb, inspect throttle cable, check for dirty jets. |
| Backfiring |
Popping sound from intake or exhaust. |
Adjust air/fuel mixture, check for exhaust leaks, and inspect timing. |
| Overheating |
Engine runs very hot, may shut down. |
Clean cooling fins, check fan operation, coolant level (if liquid cooled), and oil. |
| Excessive exhaust smoke |
Blue = burning oil, Black = rich fuel, White = coolant (rare). |
Check piston rings, valve seals, and carb tuning depending on smoke color. |
| Transmission won’t shift properly |
Difficulty engaging or changing gears. |
Inspect gear selector, clutch adjustment, oil level and quality. |
| Clutch slipping |
Engine revs but ATV doesn’t accelerate well. |
Adjust or replace worn clutch plates and springs. |
| Grinding noise while shifting |
Unusual grinding or clunking during gear changes. |
Check clutch operation, transmission oil, and shifter components. |
| Battery discharges quickly |
Battery drains while riding or won’t hold charge. |
Test stator, regulator/rectifier, and battery condition. |
| Starter motor not working |
No response or very slow turning from the starter. |
Inspect starter relay, battery, starter motor, and ground cable. |
| Lights or electronics not working |
Headlight, brake light, or indicators fail. |
Check bulbs, fuses, wiring harness, and switches. |
| 4WD not engaging (if applicable) |
4-wheel drive switch doesn’t activate system. |
Inspect actuator, wiring, 4WD switch, and front diff engagement system. |
| Fuel leak |
Strong fuel smell or visible drips. |
Inspect fuel tank, petcock, carb, and fuel lines for cracks or loose fittings. |
| Brakes feel weak or unresponsive |
Soft brake lever/pedal or long stopping distance. |
Bleed brake lines, replace pads/shoes, inspect master cylinder and fluid. |
| Chain/sprocket noise or wear |
Rattling sound or poor chain engagement (for models with chain drive). |
Lubricate chain, adjust tension, and replace worn sprockets. |
| Suspension noise or rough ride |
Squeaks, knocks, or harshness over bumps. |
Grease suspension points, check shocks and replace worn bushings. |
| ATV pulls to one side |
Vehicle veers when riding straight. |
Check tire pressure, wheel alignment, and inspect steering components. |
| Excessive vibration or noise |
Shaking or rattling from engine or frame. |
Inspect motor mounts, driveshaft, and loose bolts or brackets. |
