Kelly - before you go getting the tin muffler box have a good look at the aluminum duct on the back side of the muffler. It should have several screw holes where the tin (actually very light steel) muffler box is held to it with screws. Often times this aluminum duct is cracked or the screw holes are wallowed and won't hold the parts of the tin box. I see Charlie at CC Specialties has the tin muffler box, and price is fairly reasonable for a brand new box. Charlie also has the aluminum duct the box mounts to but make sure you're sitting down if you need one.
Also, David Kirk at "Kirk Engines" (linked above at the colorful boxes too) has an item he calls the Muffler "Krutch", ops guess he really calls it Crutch. This thing really works and will save your aluminum duct plate from cracking. See it at this link.
Specializes in garden tractor performance parts for Kohler engines and garden tractor pulling including Cub Cadets, John Deeres and morewww.kirkengines.com
Interesting- thanks for the guidance and I will check this!Use original length bolts and a new nylock nut on each bolt, tighten so that 1-2 threads shows through the nut. If you use the included instructions, you will probably overtighten them.
They also will "break in" a bit after a few hours. Make sure the engine is running 3600 RPM at full throttle too...they are really designed to damp out the engine vibrations at that speed, so if the high speed stop is not set right, it may not be operating in the optimal damping range for the mounts.
Welcome Kelly - your 680 looks like a nice machine (from the distance in your pic). When are you planning to retire (and restore)?
2026!! but, if I can somehow finance a shop before then I will restore starting at that moment. I hate to my machines sitting out in the weather under cover