Suzuki LT-Z400 2003 - RADIATOR; CARBURETOR

SERVICING INFORMATION 8-5
Complaint
Symptom and pos s ible causes
Remedy
Engine overheats.
1. Carbon buildup on piston crown.
Clean.
2. Insufficient amount of engine oil.
Check level and add .
3. Defective oil pump.
Replace.
4. Clogged oil circuit. Clean.
5. Float chamber fuel level too low.
Adjust float height.
6. Air leakage from intake pipe.
Tighten
or replace.
7. Incorrect engine oil.
Change.
6. Defective cooling system.
See radiator section.
RADIATOR
Complaint Symptom and po ssi ble causes
Remedy
Engine overheats. 1. Not enough engine coolant. Add coolant.
2. Radiator core clogged. Clean.
3. Defective temperature switch. Replace.
4. Clogged engine coolant passage. Clean.
5. Air trapped in the cooling circuit. Bleed out air .
6. Defective water pump. Replace.
7. Incorrect engine coolant.
Replace.
6. Defective cooling fan thermo-switch. Replace.
9. Defective thermostat. Replace.
Engine overcools . 1 . Extremely low ambient temperature. Install radiator cover.
2. Defective cooling fan thermo-switch. Replace.
3. Defective thermostat. Replace.
CARBURETOR
Complaint Symptom and possible causes Remedy
Starting difficulty . 1 . Clogged starter jet. Clean.
2. Clogged starter jet passage. Clean.
3.
Air leaking from joint between starter body and carbure- Tighten, adjust, or replace gas-
tor.
ket.
4.
Air leaking from carburetor joint or vacuum hose jOint. Tighten or replace defective
part.
5. Improper working starter (enricher) plunger.
Adjust.
Idling or low-speed 1. Clogged or loose pilot jet.
Clean
or tighten.
trouble . 2. Clogged or loose pilot air jet.
Clean
or tighten.
3.
Air leaking from carburetor joint, vacuum pipe joint, or Tighten or replace defective
starter.
part.
4.
Clogged pilot outlet port. Clean.
5. Clogged bypass port.
Clean.
6.
Starter (enricher) plunger not fully closed. Adjust.
Medium or high- 1. Clogged main jet. Clean.
speed trouble . 2. Clogged main air jet.
Clean.
3.
Clogged needle jet. Clean.
4.
Improper working throttle valve. Adjust.
5.
Clogged fuel filter. Clean or replace.
Overflow and fuel 1.
Worn or damaged needle valve. Replace.
level fluctuations . 2.
Broken needle valve spring. Replace.
3.
Improper working float. Adjust or replace.
4. Foreign matter on the needle valve.
Clean or replace with needle
valve seat.
5.
Incorrect float chamber fuel level. Adjust float height.