Name that mystery noise!

[dilated]

My 82 CBX is making the strangest noise. I mean weird weird. Scenario is like this, decellerating after traveling at speeds over 30 mph, pull in the clutch, as I'm dropping down through the gears, lets just say from 4th to 1st, clutch still in, no engine braking, regular wheel braking, usually around 10 mph and going from 3rd to 2nd, sometimes 2nd to 1st, I hear this short, rattleling, vibrating sound from the engine area. It almost sounds like an electric razor held up against a tin roof. Or someone sticking something into a fan. Wish I could record it so you can hear. First time I heard it I thought someone with an odd horn was honking at me. Does anything pop into your heads? I'm not sure where to go with this one. Clutch?

[cbxchris]

front sprocket loose??

[EMS]

Alternator clutch and/or bearing. Most likely the latter on its way to the eternal hunting grounds. Experienced exactly the same on my 81 X

[dilated]

Thanks for the replies. I was suspecting the alternator bearing too. I recently replaced the alt spring and clutch plates but didn't bother with the bearing. Has about 36k on it. I'll let you know what I find this weekend. It certainly is an odd sound.