Yamaha YZ250X 2022 Owner's Service Manual page 246

Symptom
—
Incorrect mid-high speed
Symptom
Spark plug does not produce a
spark
Fuel not supplied
Possible cause
Damaged or worn needle valve
Incorrect fuel level
Bent, worn, or damaged starter
plunger
Incorrectly adjusted starter cable
Clogged or damaged carburetor
breather hose
Incorrect throttle position sensor
angle
Failed air induction system
Clogged vacuum hose
Cracks and damage in vacuum
hose
Damaged carburetor joint
Loose carburetor joint
Clogged air filter element
Possible cause
Incorrect spark plug gap
Worn or damaged spark plug
Defective spark plug cap
Defective ignition coil
CDI unit failure
Fuel leakage
Clogged carburetor fuel passage
Clogged needle valve or needle
valve seat
Damaged float
9-3
TROUBLESHOOTING
Actions
Replace the needle valve.
Adjust the fuel level to the proper
level.
Replace the starter plunger.
Adjust the starter cable.
Clean, repair, or replace the car-
buretor breather hose.
Adjust the throttle position sensor
angle.
Check the air induction system.
Repair or replace faulty parts.
Clean the vacuum hose.
Replace the vacuum hose.
Replace the carburetor joint.
Tighten the carburetor joint bolts
to the specified torque.
Clean or replace the air filter ele-
ment.
Actions
Adjust the spark plug gap.
Replace the spark plug.
Replace the spark plug cap.
Replace the ignition coil.
Replace the CDI unit.
Check the fuel passage. Repair or
replace as necessary.
Clean the carburetor.
Clean the needle valve or needle
valve seat.
Replace the float.