Motorcycle Repair: 93 kawasaki zx7 ninja, kawasaki zx7, gear wheels

Question
I keep hearing this loud whining noise only when moving. It comes and goes. It seems to happen more when the tach is at 5000 rpm or higher doesnt matter what gear I am in or what speed. when I slow to a stop it gets softer then fades away at the stop?  

Answer
Hi Warren,

The noise you're hearing is normal.

The clutch hub gear is straight-cut. The noise is caused by the angle in which gears are cut. Straight-cut gears tend to make a whine sound as they rotate.

Helical-cut gears tend to be more quiet. The teeth are cut at an angle, allowing for more gradual, hence smoother meshing between gear wheels, eliminating the whine characteristic of straight-cut gears.

If you notice any change in the noise, have a local tech inspect your Ninja.

Respectfully,
Mark Shively