Suzuki TU250X Service Manual page 325

Complaint
Engine runs poorly
in high speed range.
Symptom and possible causes
Defective engine internal/electrical parts
1. Weakened valve springs
2. Worn camshaft
3. Valve timing out of adjustment
4. Too narrow spark plug gap
5. Ignition not advanced sufficiently due to poorly
working timing advance circuit
6. Defective ignition coil
7. Defective CKP sensor
8. Defective ECM
9. Clogged air cleaner element
10. Clogged fuel hose, resulting in inadequate fuel
supply to injector
11. Defective fuel pump
12. Defective TP sensor
13. Defective STP sensor or STVA
Defective air flow system
1. Clogged air cleaner element
2. Defective throttle valve
3. Defective secondary throttle valve
4. Sucking air from throttle body joint
5. Defective ECM
6. Defective STP sensor or STVA
Defective control circuit or sensor
1. Low fuel pressure
2. Defective TP sensor
3. Defective IAT sensor
4. Defective CKP sensor
5. Defective IAP sensor
6. Defective ECM
7. TP sensor out of adjustment
8. Defective STP sensor and/or STVA
SERVICING INFORMATION 10-5
Remedy
Replace.
Replace.
Adjust.
Adjust.
Replace ECM.
Replace.
Replace.
Replace.
Clean.
Clean and prime.
Replace.
Replace.
Replace.
Replace.
Adjust or replace.
Adjust or replace.
Retighten or replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.