The machine changed hands a few times before it made it to our shop but we're guessing the bearing got the shaft that hot that the belt tension just folded it over but that still seems pretty far-fetched. We'll probably never know for sure haha
Does the chipper condition match the hours? A lot of times the autofeed tachs get changed and the hours from the old tach don't get programmed into the new one. If it's super nice, they're probably original, if it looks like it has 5000 hours on it, it probably does.
Those engine are internally balanced and if that balancer goes it is catastrophic. You might have something going on there or an injector out causing a miss. I would definitely get it to someone for a second opinion.
We have had quite a few of them through here now and overall I think they're pretty good, especially for what you can buy them for compared to other brands. We have a handful in stock right now if you want to head over to our website there should be a bunch of pictures of each model!