Shame on you for not making a sketch of how it is routed!
Any way, some more info is needed, such as name of machine, where you bought it, and other pertinent info, engine size, other stuff.

Yard Pro was made by AYP (Electrolux then Husqvarna). If you have the model number (under the seat, on a label) you should be able to get an exploded diagram from Sear Parts website.

Without a model number, it's hard to help you further.

Here is a link that might be useful: Sears Parts Direct

If you can't find the model number, try doing a Google image search for "yard pro lt 12" and when you find the picture of the tractor that looks just like yours, see if it says the model number.

Here is a link that might be useful: DIY Lawn Mower Repair Blog