Topic: Strange noise after spark plug change

[crobar]

78 cb550. Changed plugs and resistor caps yesterday. Warmed it up after and am getting a strange noise at high revs. I'll rev it high and behind the engine noise comes a sound sort of like a high pitch grinding but not exactly a grinding. Hard to describe. Goes away as revs drop but stays constant if revs stay up.

Changing oil right now, no sign of flakes in the oil. Any thoughts?

[BomberMann650]

Really shouldn't high rev the motor in neutral.

You could be hearing clutch or cam chain noise. 

[754]

Pop your outboard valve inspection caps, look for silvery powder ..top of valve spring should be wet.

[crobar]

I'll change my description to a whirring sound if that makes a difference?

[Deltarider]

Verify you're in neutral and not some sort of false neutral. Have you been at the camchain tensioner lately?

Hard to describe.

Than it's hard to determine for us. Could be the mirrors vibrating, a dito loose dynamo cover, a not tightened ignition cover.