First just the correct number on the belt doesn't mean it is the correct belt so when in doubt measure it. This one is 5/8 x 97.5 OD. Aftermarket are especially bad about having the correct belt number imprinted but on a belt the wrong size. I quit Sunbelt (A&I) because of this. Nearly every 5/8 belt I got from them was nearly 2" short. Impossible to get them when they are this short.
Second with an electric PTO setup normally the idler spring must be removed to install the correct belt. The spring is reinstalled once the belt is in place. To do this you need a spring hook tool.
But this deck was originally a manual PTO setup. All they did was to install a fixed engagement cable and spring. So it is more of a pain to install the belt then usual. Basically you install the belt on all the pulleys except one of the deck spindle pulleys. Then you walk on the deck belt on the last pulley or using something around the idler pulley center bolt pull it forward to remove the tension on it caused by the spring. Item 61 is the spring assembly.
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The bolt I am referring to is item 146. It protruding above the pulley (item 145). Just be careful to only stretch item 61 enough to get the belt on. Here I still use my spring hook to remove and install item 61 just I have the tool available.
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