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1A-9 Engine General Information and Diagnosis:
Engine lacks power
(Defective engine internal/
electrical parts)
Loss of tappet clearance.
Adjust.
Weakened valve springs.
Replace.
Valve timing out of adjustment.
Adjust.
Worn piston rings or cylinder.
Replace.
Poor seating of valves.
Repair.
Fouled spark plug.
Clean or replace.
Incorrect spark plug.
Adjust or replace.
Clogged fuel injector.
Clean.
TP sensor out of adjustment.
Adjust.
Clogged air cleaner element.
Clean.
Sucking air from throttle valve or
vacuum hose.
Retighten or replace.
Too much engine oil.
Drain out excess oil.
Defective fuel pump or ECM.
Replace.
Defective CKP sensor and ignition coil.
Replace.
Engine lacks power
(Defective control circuit
or sensor)
Low fuel pressure.
Repair or replace.
Defective TP sensor.
Replace.
Defective IAT sensor.
Replace.
Defective CKP sensor.
Replace.
Defective IAP sensor.
Replace.
Defective GP sensor.
Replace.
Defective ECM.
Replace.
TP sensor out of adjustment.
Adjust.
Engine overheats
(Defective engine internal
parts)
Heavy carbon deposit on piston crown.
Clean.
Not enough oil in the engine.
Add oil.
Defective oil pump or clogged oil circuit.
Replace or clean.
Use of incorrect engine oil.
Change.
Sucking air from intake pipe.
Retighten or replace.
Defective cooling system.
Refer to “Engine Cooling Symptom Diagnosis
in Section 1F (Page 1F-4)”.
Engine overheats (Lean
fuel/air mixture)
Short-circuited IAP sensor/lead wire.
Repair or replace.
Short-circuited IAT sensor/lead wire.
Repair or replace.
Sucking air from intake pipe joint.
Repair or replace.
Defective fuel injector.
Replace.
Defective ECT sensor.
Replace.
Engine overheats (The
other factors)
Ignition timing too advanced due to
defective timing advance system (ECT
sensor, GP sensor, CKP sensor and
ECM.)
Replace.
Drive chain is too tight.
Adjust.
Dirty or heavy exhaust
smoke
Worn piston rings or cylinders.
Replace.
Too much engine oil in the engine.
Check and drain excess oil.
Worn valve guides.
Replace.
Scored or scuffed cylinder wall.
Replace.
Worn valves stems.
Replace.
Defective stem seals.
Replace.
Worn oil ring side rails.
Replace.
Condition
Possible cause
Correction / Reference Item
PartShark.com
877-999-5686
Summary of Contents for LT-Z400
Page 2: ...P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 4: ...P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 62: ...0C 9 Service Data P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 296: ...1K 6 Exhaust System P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 358: ...3A 18 Drive Chain Drive Train Drive Shaft P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 408: ...4D 5 Parking Brake P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 460: ...6B 13 Steering Handlebar P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 490: ...P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 491: ...P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...