Ii had a question about the Kirby Dual Sanitronic 50.I recently found a Tan Model that seems to be in good condition externally but when it starts it whistles after it gets up to full speed it stops and then does it again as it slows down to a stop.Funny really it sounds like a jet aircraft.My question is are the Bearings failing or has anybody experienced this due to the fan plate rubbing.I kind of figured if it was the fan plate on the axle it would do it all the time.Is it time for a rebuild or just a good cleaning?

