Whirring noise when on clutch ?

Question

After last weeks hare scrambles, my kdx was kind of hot and the clutch was making that whirring noise I hear on so many other bikes. Time to change the throwout bearing ?

Answer 1

The whirring noise is usually the outer basket gears cutting through the oil while meshing with the primary gear.
Some street bikes have changed from straight cut gears to angle cut, to lower the noise.
When your bike gets hot, the oil thins out a little.
Move up to the next weight oil.
If that doesn't help -
Remove the clutch and check the condition of the gears.
Check the condition of the washer between the inner & outer basket. And the one behind the outer basket.
Check the condition of the bushing of the outter basket and the surface of the basket it rides on.

Answer 2

change the entire clutch shaft