Troubleshooting; Troubleshooting Of Engine - Yamaha YZ250 2022 Owner's Service Manual

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
Spark plug does not produce a
spark
Fuel not supplied
—
Possible cause
Refer to "TROUBLESHOOTING" under "IGNITION SYSTEM" on page
8-2.
Empty fuel tank
Clogged fuel tank cap breather
hole
Clogged or damaged fuel hose
Fuel leakage
Clogged fuel cock strainer
Clogged fuel cock
Cracked, damaged or worn fuel
cock
Clogged carburetor fuel passage
Clogged needle valve or needle
valve seat
Damaged float
Clogged pilot jet
Clogged starter jet
Bent or damaged starter plunger
Incorrectly adjusted starter cable
Water or foreign material in fuel,
degraded fuel
9-1
TROUBLESHOOTING
Actions
Fill the fuel tank with fuel.
Clean the fuel tank cap.
Clean, repair, or replace the fuel
hose.
Check the fuel passage. Repair or
replace as necessary.
Clean or replace the fuel cock
strainer.
Clean or replace the fuel cock.
Replace the fuel cock.
Clean the carburetor.
Clean the needle valve or needle
valve seat.
Replace the float.
Clean the pilot jet.
Clean the starter jet.
Replace the starter plunger.
Adjust the starter cable.
Change fuel.