Tacho or Speedo Cable issue

[Jean]

You wouldn't happen to have drilled brake rotors would you?
THEY whiz too.

[2valve]

Good call there jean, forgot all about that one !
Jeff , as jean has mentioned you do get the WHIZ sound when the S/S drilled disc rotors are wet when applying the brakes, personally have forgotten all about that noise . If you wet the discs and take the bike for a quick spin and apply the brakes you'll hear the noise.

[boxertwinjeff]

Yes Jean, It has the drilled Rotors, being a '76 Model, but the sound does appear to be coming from the Instrument
console,... I'll disconnect the Speedo & Tacho cables and spray some Lithium grease in there as suggested, to see
if its just a lack of lube issue.

[Jean]

Could also be coming from the cables...Just disconnect cables first and go for a short ride. See if whiz noise is still there.
You might have a cable going bad and all the lube in the world in the instrument heads won't stop that!
On the other hand, all my bikes are REALLY-REALLY old and the cables have not made any noises.....yet. Their protective sheathing is not broken tho so no water has gotten in.