| Problem |
Description |
Solution |
| Engine won’t start |
No crank or click when pressing the start button. |
Check battery voltage, kill switch, ignition switch, starter relay, and fuses. |
| Engine cranks but doesn’t start |
Engine turns over but does not fire. |
Check spark plug, fuel supply, clean or inspect carburetor, check compression. |
| No spark |
Spark plug does not ignite. |
Test CDI, ignition coil, stator, and inspect wiring and connections. |
| Weak or intermittent spark |
Spark is weak or cuts in and out. |
Replace spark plug, inspect coil, check CDI, verify ground connection. |
| Hard to start (cold or hot) |
Engine requires repeated attempts to start, or throttle manipulation. |
Clean carburetor, inspect choke system, check air filter and fuel lines. |
| Engine starts, then stalls |
Engine runs briefly, then shuts off. |
Clean idle circuit, check fuel flow, adjust idle speed, check vacuum lines. |
| Rough or unstable idle |
Engine idles irregularly or stalls at idle. |
Adjust idle screw, clean idle circuit, inspect vacuum lines for leaks. |
| Poor acceleration / low power |
Sluggish throttle response or poor top-end performance. |
Clean air filter, inspect throttle cable, clean or adjust carburetor jets. |
| Backfiring (intake or exhaust) |
Loud popping sound from exhaust or intake during deceleration or throttle input. |
Check for air leaks, adjust carburetor, check exhaust for leaks. |
| Overheating |
Engine runs hot or fan doesn’t turn on. |
Check radiator, cooling fan, coolant level, thermostat, and oil level. |
| Excessive exhaust smoke |
Blue smoke (oil burn), black smoke (rich fuel mixture), or white smoke (coolant). |
Blue: Check valve seals and rings. Black: Adjust carburetor. White: Inspect head gasket. |
| CVT slipping |
Engine revs but there is poor or delayed acceleration. |
Inspect CVT belt, clean clutch sheaves, adjust or replace worn belt. |
| Transmission won’t shift smoothly |
Gears feel sticky or hard to engage. |
Check shift linkage, clutch adjustment, inspect transmission fluid. |
| Grinding noise when shifting |
Grinding sound when shifting into gears. |
Inspect clutch operation, CVT sheave wear, and transmission oil. |
| Battery drains quickly |
Battery loses charge even when riding. |
Test stator output, regulator/rectifier, and battery. |
| Starter motor not turning |
Starter motor is not responding or turning slowly. |
Test battery, starter solenoid, starter motor, and wiring connections. |
| Lights or electronics not working |
No lights, fan, or display on the dashboard. |
Inspect fuses, switches, and wiring harness for faults or corrosion. |
| 4WD not engaging (if applicable) |
Front wheels do not engage when switching to 4WD. |
Check 4WD actuator, 4WD switch, front differential, and wiring. |
| Fuel leak |
Gasoline smell or fuel leaking from carburetor or tank. |
Inspect fuel lines, tank seals, carb overflow, and fuel petcock. |
| Spongy or weak brakes |
Brake pedal or lever feels soft or weak, poor stopping power. |
Bleed brake lines, check brake fluid level, inspect brake pads/shoes. |
| Brake noise |
High-pitched squealing or grinding sound when braking. |
Replace worn brake pads, clean rotors, and inspect for debris or warped parts. |
| Excessive vibration or rattling |
Unusual shaking, rattling, or noise during riding. |
Check engine mounts, driveshaft, wheels, and loose bolts or bearings. |
| ATV pulls to one side |
ATV veers left or right when riding or braking. |
Check tire pressure, suspension, steering alignment, and brake drag. |
| Suspension feels harsh or noisy |
Rough ride or squeaking sounds over bumps or rough terrain. |
Grease suspension pivots, inspect and replace shocks, check for worn bushings. |
| Cooling fan not operating |
Engine overheats but fan does not turn on. |
Test fan motor, temperature sensor, relay, and wiring connections. |
