Small Engines (Lawn Mowers, etc.): Toro excessive deck drive vibration, spindle bearings, loose bolts

Question
Have 44" Toro,when blades are engaged the blade drive belt flaps about causing vibration. mower cuts OK,idler pulleys are OK,no apparent damage to belt. Belt appears to have reasonable tension when engaged.Spindle bearings not noisy.no damage to mandrels.

Answer
This can be caused from a bump in the belt where the two halves are fused together.  Run your hand along the belt and see if you feel about.  Next would be belt guides.  All belt guides  are in-place and 1/8 inch of the belt when operating.  Next would be a broken Pulley or bad, Pulley tearing or a broken weldment.  You could remove the deck and belt and run the engine to see if there is any wobble in the drip holy at the same time check for any loose bolts or broken well.  If it was not doing it before and started doing it there has to be a reason the best way to find follow what from the clutch to the deck.  Good luck.