The 2003-2005 Yamaha YZF-R6 sportbike repair manual by Haynes, covers models indicated and powered by four-stroke, 16-valve, 600cc in-line four cylinder engines.
Book Excerpt: 2003-2005 Yamaha YZF-R6 Repair Manual COOLING SYSTEM

General information The cooling system uses a water/antifreeze mixture to carry excess heat away from the engine. The cylinders are surrounded by a water jacket, through which the coolant is circulated by thermo syphonic action in conjunction with a water pump. The water pump drives off the oil pump which is driven by chain and sprockets off the back of the clutch. Heated coolant rises through the system to a thermostat and then to the radiator. It flows across the radiator, where it is cooled by the air flow, then down to the water pump and back into the engine, where the cycle is repeated. The thermostat is fitted in the system to prevent the coolant flowing through the radiator when the engine is cold, therefore accelerating the speed at which the engine reaches normal operating temperature. A coolant temperature sensor is fitted into the back of the cylinder head which provides signals for the coolant temperature display on the instrument panel and for the ECU as part of the engine management system.

ELECTRICAL SYSTEM

IGNITION (MAIN) SWITCH CHECK

1. Remove the air filter housing (see Chapter 4). Trace the ignition (main) switch wiring back from the switch and disconnect it at the white connectors (see illustration). Make the checks on the switch side of the connector.
2. Using a multimeter or a continuity tester, check the continuity of the connector terminal pairs (see Wiring Diagrams at the end of this Chapter). Continuity should exist between the terminals connected by a solid line on the diagram when the switch key is turned to the indicated position.
3. If the switch fails any of the tests, replace it with a new one.
REMOVAL
4. Disconnect the battery negative (-) lead. Remove the air filter housing (see Chapter 4), trace the ignition (main) switch wiring back from the switch and disconnect it at the connectors (see illustration 18.1). Release the wiring from any cable ties and feed it back to the switch noting the correct routing. Where an immobilizer is fitted, disconnect its wiring at the connector (see illustration 21.27b in Chapter 4).

Subject: 2003, 2004, 2005 Yamaha YZF-R6 service, maintenance, repair. ISBN-10: 1844256014 | ISBN-13: 9781844256013 | Haynes 4601