Troy Bilt chipper shredder

I assume, since we don't have any responses, that no one here has your exact chipper. There's something you can do, however, that will make it more likely you get an answer, namely, tell us which engine is in the machine. Just saying "8HP" is not enough, at least not for me. Look around for numbers. In all likelihood we can come up with a parts diagram, which while it won't be a photo of the linkage, will point out how many springs you should have and what the part number is. It might also help if you offered a photo of the linkage as you now have it; maybe the answer is obvious to some of us. Finally, you could search YouTube videos for someone repairing a chipper similar to yours. He'll probably be fiddling with the carburetor and, if you're lucky, he'll have a close-up of the carburetor and linkage as he reinstalls it.