Craftsman mower won't stop moving !!!!

I just installed a new drive belt on my Craftsman LT2000 (model: 247.288841) - not an easy job with the odd tensioner and variable speed pulley on this model. But, it's done and looks like everything is routed according to the diagram. However, this new belt is so thick and stiff, the tractor immediately starts moving forward when shifted into forward - no pedal push required. AND, there's no stopping it. The brakes aren't strong enough. I even cleaned and adjusted the brakes as tight as they can be and I still cannot stop. I even replaced the brake unit. The belt is a 954-0467A which is what it calls for. When I took off the old belt it seemed to me to be not as wide as the replacement. I figured it was just wear. The picture is in neutral with the engine off.


ne off,