Suzuki LT-Z400 - Radiator; Carburetor

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