Need to see how to put blade belt on riding mower 54 cut model no 9602500020 husgvarna

mtd website should have this diagram

You have probably thrown the belt for the blades. If it continues to throw the bet check the tensioner.

Sounds like it's just overloaded. I would sharpen the blades to make cutting easier, ( that really helped with mine ). Good Luck .

Here is a link to the complete manual for your machine. Good luck!

Your owners manual should have a diagram. If you don't have the manual, you can download one here. You will just need the Craftsman model number of your machine.
http://www.searspartsdirect.com/partsdirect/product-types/Riding-mower-tractor-Parts

You need model number and serial number. Look at www.searspartsdirect.com. Once you locate your parts list for your model, look on right side of web page and see if there is a link to a manual for this model. If so it should have a diagram.

http://www.ereplacementparts.com/ type in model number of your mower ie 40560x50c All parts and diags ypu need ,Yours Henry

54" deck on AYP/Husqvarna

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

Your forward speed may be too fast for the mower blades to cut every blade of grass. It may be new, but check the deck to see if there are any dents pushing the quill assemblies up making the deck cut uneven. Or it may have the wrong blades on it.
I have seen this problem in the past with a Gravely mower. The person was trying to cut grass to fast. He sold the unit and the new onwer did not noticed any the problems the old owner described.

It sounds to me that you need a new mower deck drive belt, or your blades need sharpening. If the blade edges are rounded, they won't cut butter... Also, when mower is off, check mower deck drive pulleys to make sure you don't have any that are locked up or are dragging. You can check this by pulling the belt away from pulley and spinning the pulley by hand. MOWER MUST BE OFF before attempting any of these checks. You would be surprised how many people would try this with the mower running.
Hope this helps