Yamaha YZ250 2022, Owner'S Service Manual

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TROUBLESHOOTING
9-1
EAM20148
TROUBLESHOOTING
EAM30309
GENERAL INFORMATION
TIP
Troubleshooting information provided here does not cover all the trouble symptoms, possible causes,
and remedial actions. Some items may not apply depending on the model. Use this information as a
guide and quick reference matrix when performing basic troubleshooting. Refer to the each chapter for
detailed information on checking, adjustment, and replacement.
EAM30612
TROUBLESHOOTING OF ENGINE
Engine will not start or is difficult to start, but it cranks.
Symptom Possible cause Actions
Spark plug does not produce a
spark
Refer to “TROUBLESHOOTING” under “IGNITION SYSTEM” on page
8-2.
Fuel not supplied
Empty fuel tank Fill the fuel tank with fuel.
Clogged fuel tank cap breather
hole
Clean the fuel tank cap.
Clogged or damaged fuel hose
Clean, repair, or replace the fuel
hose.
Fuel leakage
Check the fuel passage. Repair or
replace as necessary.
Clogged fuel cock strainer
Clean or replace the fuel cock
strainer.
Clogged fuel cock Clean or replace the fuel cock.
Cracked, damaged or worn fuel
cock
Replace the fuel cock.
Clogged carburetor fuel passage Clean the carburetor.
Clogged needle valve or needle
valve seat
Clean the needle valve or needle
valve seat.
Damaged float Replace the float.
Clogged pilot jet Clean the pilot jet.
Clogged starter jet Clean the starter jet.
Bent or damaged starter plunger Replace the starter plunger.
Incorrectly adjusted starter cable Adjust the starter cable.
—
Water or foreign material in fuel,
degraded fuel
Change fuel.