KTM 690 - Engine overheats.

TROUBLESHOOTING 73
Faults Possible cause Measure
The engine cannot be cranked (electric
starter).
Main fuse burned out – Remove the main fuse. ( P. 62)
– Fit the main fuse. ( P. 62)
Low external temperature – Recharge the battery. Establish the
reason for discharging or have it
checked in a KTM workshop.
Engine does not speed up. Carburetor running over because float
needle dirty or worn.
– Have carburetor checked.
Loose carburetor jets – Have carburetor checked.
Electronic ignition adjustment defective – Have ignition system checked.
Engine has no idle. Idling jet blocked – Clean carburetor.
Adjusting screws on carburetor distorted – Have the carburetor adjusted.
Spark plug defective – Change spark plug.
Ignition system defective – Have ignition system checked.
Engine stalls or is popping into the carbu-
retor.
Lack of fuel – Clean and check the fuel system and
carburetor.
Engine takes in bad air – Check rubber sleeves and carburetor
for tightness.
Engine overheats. Too little coolant in cooling system – Check the cooling system for leakage.
– Check the coolant level. ( P. 63)
Too little air stream – Switch off engine when standing.
Radiator fins very dirty – Clean radiator fins.
Bent radiator hose – Replace the radiator hose.
Thermostat defective – Have thermostat removed and checked.
Specification
70 °C (158 °F)
Defect in radiator fan system – Have the radiator fan system checked.
Engine has too little power. Fuel feed interrupted – Check the tank breathers.
– Check the fuel filter.
– Have the fuel screen of the tanks
checked.
– Clean fuel tap.
– Clean carburetor.
– Have the fuel pump checked.
Air filter very dirty – Clean the air filter. ( P. 65)
Exhaust system leaky, deformed or too
little glass fiber yarn filling in main
silencer.
– Check exhaust system for damage.
Valve clearance too little – Have valve clearance adjusted.
Electronic ignition adjustment defective – Have ignition system checked.
High oil consumption Engine vent hose bent – Route the vent hose without bends or
replace it if necessary.
Engine oil level too high – Check the engine oil level. ( P. 67)
Engine oil too thin (low viscosity) – Change the engine oil and oil filter,
and clean the oil screen. ( P. 67)