Reply To: Bike Can Only Start If I Rev The Throttle – GT250R 2013
IAT = Air intake temperature sensor (for airbox) checks the air inside and reports back to ECU
ET = Engine Temp Sensor , it is on the Front Cylinder Header under the metal manifold.
Service manual would usually tell you where these things are and how to test them properly , the IAT would just need to know OMHS readings not voltage.
(Heat changes the resistance = so ECU would know if the resistance goes up , it means air is less dense as more heat reduces oxygen density)
So i would definitely follow the manual checking sensors 1 by 1 first. Some sensors only need ohms readings. If you applied voltage to them, it fries them and you will need to replace them again.