Hi,
The Yamaha YP-4 turntable that I've owned for years has developed a bad case of Wow. Note pitch seems to waver quite a bit. The wow sounds once per 33 rpm and lasts for maybe 20% of each rotation. The drive belt is fairly new. I cleaned the pully on the motor, greased the center spindle. The problem seemed fixed for all of 10 miutes then returned. I've leveled the turntable. The tonearm has not been abused. Any helpful advice is appreciated.