Mark, I included a fix Maxkirby used to fix his case a few years ago. Here is the LINK. The 4rd last post has a link to some photos. He found that the idler shaft was hollow, so he fitted a pin inside the idler shaft then drilled out the engine case and outer cover to accept the pin. Worked for him. Details in the post.

Can't hurt to try.

Here are the photos





One other thing. If you did replace the engine case, you would need the top and bottom portions since they are a matched machined set to accommodate the main crank bearings.

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