Kawasaki KFX 50

Covered Models

  • 2003 Kawasaki KFX 50
  • 2004 Kawasaki KFX 50
  • 2005 Kawasaki KFX 50
  • 2006 Kawasaki KFX 50
  • 2007 Kawasaki KFX 50
  • 2008 Kawasaki KFX 50
  • 2009 Kawasaki KFX 50
  • 2010 Kawasaki KFX 50
  • 2011 Kawasaki KFX 50
  • 2012 Kawasaki KFX 50
  • 2013 Kawasaki KFX 50
  • 2014 Kawasaki KFX 50
  • 2015 Kawasaki KFX 50
  • 2016 Kawasaki KFX 50
  • 2017 Kawasaki KFX 50
  • 2018 Kawasaki KFX 50
  • 2019 Kawasaki KFX 50
  • 2020 Kawasaki KFX 50
  • 2021 Kawasaki KFX 50
  • 2022 Kawasaki KFX 50
  • 2023 Kawasaki KFX 50
  • 2023 Kawasaki KFX 50
  • 2025 Kawasaki KFX 50

Kawasaki KFX 50

GENERAL DATA
Producer Kawasaki
Model KFX 50
Year
2003 – 2025

Image Kawasaki KFX 50

TEHNICAL SPECIFICATIONS

ENGINE
Type SOHC single cylinder, 4-stroke, air-cooled
Displacement 49.5 cm3 (3.02 cu in)
Bore × Stroke 39×41.4 mm ( (1.54×1.63 in)
Compression Ratio 10.8: 1
Starting System Electric and kick starter
Carburetor PTE 16 mmφ / Keihin PTE 16
Ignition System CDI or Battery & Coil (Transistorized Ignition)
Ignition Timing 13° BTDC @2 000 r/min (rpm)
Spark Plug NGK CR7HSA
Engine Oil Type API SE, SF or SG
Lubrication System Forced lubrication (wet sump)
Engine Oil Capacity 0.8 L (0.85 US qt)
Maximum speed 15 mph (24 km/h)
DIMENSIONS
Overall Length 1 400 mm (55.12 in)
Overall Width 880 mm (34.65 in)
Overall Height 2003-2022: 910 mm (35.83 in)
2023-2025: 885 mm (34.8 in)
Wheelbase 965 mm (37.99 in)
Track: Front 690 mm (27.17 in)
Track: Rear 700 mm (27.56 in)
Ground Clearance 2003-2022: 85 mm (3.35 in)
2023-2025: 75 mm (3.0 in)
Curb Mass 2003-2022: 111 kg (245 lb)
2024-2025: 113 kg (249 lb)
TRANSMISSION
Transmission Type Automatic centrifugal type
Clutch Type Belt drive torque converter (CVT)
Driving System Chain Drive
Primary Reduction Ratio 0.913.03
Final Reduction Ratio 2 (32/16)
Transmission Oil SAE 90
Transmission Oil Capacity 0.12 L (0.13 US qt)
CHASSIS
Type Double cradle, steel
Fuel Tank Capacity 2007-2016 Models: 5.5 L (1.45 US gal)
2017-2025 Models: 5.3 L (1.40 US gal)
TIRES, RIMS & BRAKES
Tire Size: Front AT16×8−7 Tubeless
Tire Size: Rear AT16×8−7 Tubeless
Rim Size: Front 7×5
Rim Size: Rear 7×5
Front brakes Single A-arm with twin shocks, providing 2.8 inches (71 mm) of travel
Rear brakes Swingarm with a single shock, providing 2.9 inches (74 mm) of travel
ELECTRICS
Battery 12 V 4 Ah
Tail/Brake Light 12 V 21 W
Headlight 12 V 21 W
SUSPENSIONS
Front Single A-arm with twin shocks, providing 2.8 inches (71 mm) of travel
Rear Swingarm with a single shock, providing 2.9 inches (74 mm) of travel
TROUBLESHOOTING
Problem Description Solution
Engine won’t start No crank or response when pressing the starter button. Check the battery, kill switch, ignition switch, starter relay, and fuses.
Engine cranks but doesn’t start Engine turns over but does not fire. Check the spark plug, fuel supply, clean or inspect the carburetor, and check compression.
No spark No spark at the spark plug when cranking the engine. Test the ignition coil, CDI unit, stator, and inspect wiring connections.
Weak or intermittent spark Spark is weak or inconsistent. Replace the spark plug, inspect the ignition coil, check the CDI, and verify the ground connection.
Hard to start (cold or hot) Multiple attempts are needed to start the engine, or throttle manipulation required. Clean the carburetor, check the choke system, inspect air filter, and fuel lines.
Starts but stalls Engine starts but shuts off after a short time. Check the fuel flow, adjust idle screw, clean the idle jet, and inspect the vacuum lines.
Rough or unstable idle Engine surges, idles unevenly, or stalls at idle. Clean the idle jet, adjust the idle screw, check for vacuum leaks in the intake manifold.
Poor acceleration or sluggish power Engine bogs down or performs poorly when accelerating. Clean the air filter, inspect the throttle cable, clean carburetor jets, and check fuel system.
Backfiring (intake or exhaust) Popping or backfiring sound from the exhaust or carburetor. Adjust the air/fuel mixture, inspect for intake or exhaust leaks, and adjust the carburetor.
Overheating Engine runs excessively hot or fan does not turn on. Inspect the radiator, cooling fan, coolant level, thermostat, and oil level.
Excessive exhaust smoke Blue smoke (oil burning), black smoke (rich fuel mixture), or white smoke (coolant). Blue: Check valve seals or piston rings. Black: Adjust the carburetor. White: Inspect for blown head gasket.
CVT slipping Engine revs high, but the vehicle accelerates poorly. Inspect the CVT belt, clean clutch sheaves, and adjust or replace the belt.
Transmission won’t shift smoothly Gears are hard to engage or shift roughly. Check shift linkage, inspect the clutch system, and check fluid levels and conditions.
Grinding noise when shifting Loud grinding sound during gear changes. Inspect CVT sheave condition, belt deflection, and clutch operation.
Battery drains quickly Battery loses charge even after riding for extended periods. Test the stator output, inspect the regulator/rectifier, and check battery condition.
Starter motor not working Starter motor doesn’t turn over or operates slowly. Check battery voltage, test the starter solenoid, starter motor, and inspect the wiring.
Electrical issues Lights, fan, or dashboard malfunction. Inspect fuses, relays, switches, and wiring harness for faults or corrosion.
Fuel leak Fuel smell or visible fuel leakage around the carburetor or fuel tank. Inspect fuel lines, tank seals, carb overflow, and petcock.
Spongy or weak brakes Brake pedal or lever feels soft or weak, poor stopping power. Bleed the brake lines, check brake fluid levels, inspect brake pads, and check for leaks.
Brake noise High-pitched squeal or grinding noise when braking. Replace worn brake pads, clean rotors, and check for debris or warped parts.
Excessive vibration or rattling Unusual shaking or noise when riding. Inspect engine mounts, driveshafts, tires, and suspension components.
Steering pulls to one side ATV veers to one side or pulls during riding. Check tire pressure, alignment, suspension, and brake drag.
Suspension feels harsh or noisy Rough ride or squeaking sounds over bumps or rough terrain. Grease suspension pivots, inspect shock absorbers, and replace worn bushings.
Cooling fan not operating Engine overheats, but fan does not turn on. Test the fan motor, temperature sensor, fan relay, and wiring connections.