I have a poulan pro ridingmower model number 960420107/pb195h42lt. It will operate well cut and all as long as I keep some tention on clutch/brake peddle.If I release it completely it will make a loud rattle like noise?I enspected the drive belt as best I could by lifting mower frunt end and feeling for any defects but belt seem OK.idler pully turns freely as far as I can tell its OK.Dose anyone have any idias I can try?

You have severalpulleys working in conjunction with your drive. You have a bad one somewhere and it may not be the idler. The belt could also have a lateral crack in it.

Thank you for the reply ballengerb1.I will remove the belt completely and enspect,but what do I look for in a pully to determen if its good of bad?

I just checked the belt again and it looks good,no craks or broken spots.I had some one sit on it and work the brake/clutch while I looked undernith.The noise is coming from the belt slaping againts one of the pullys just as the clutch is almost completely releast.I can ride the clutch just so there is enough tention to where the belt won't slap and it dose well that way I can cut with out a problem as long as I keep that bit of tention on,once I take my foot off the clutch the slaping starts? Is the belt too long,is there an adjusten on the peddle itself,what can I do?

Check that pulley , check all pulleys , take all tension off and spin pulleys by hand , if you hear or feel anything besides a smooth operation replace it , should not make any noise.
Luck

I wonder if this could just be the belt that is stretch out?Because once I disengage the break clutch completely the belt starts slaping against the pully making that rattling niose.? I press the break/clutch just slitely and its smooth sailing,I can cut my entier lawn with out noise.Could it be a spring on the clutch itself?? Why dose the belt lose tention like that once the clutch is completely disengaged?All pullys spen freely,and seem normal.I will take the belt to sears and compare it to a new one and go from there.Thank you folks for the advice. Will let you know how it gos from here.
SLYME65