I would say that even though your belt is not slipping,those are the symptoms of a worn stretched belt.Not starting immediately is one of the first signs.
9 responses Add your response
New Belt. Really. That's all you need. Been there and done that with a slow P25. I wouldn't believe it was the belt and I tried a dozen other suggested fixes.
Finally I ordered a new belt and that was all it took.
PS. To check the pulley just try grabbing the pulley with your hand with the motor running and see if it slips on the motor shaft. If it's that a drop of super glue on top of the pulley where you see the moto shaft is supposed to stop the slipping. Notice: people that have tried this have also gotten superglue inside the motor and ruined the motor.