Steve, Devcon is good, and there are a few alternatives. I don't use Devcon because I've found an epoxy that works just as well and sets faster. I've tried about 10 brands of epoxy metal and many just don't seem to be up to the job of living inside a two stroke mota on full volume. I've even had Devcon start to peel off.

Remember what I said about drilling the casing and maybe even using screws or something to hold it all together. Better to butcher a set of F3 cases than destroy an F3 crank cos the epoxy fell off!

One tip. All epoxies that I've tried have a various amount of shrinkage while curing. With this in mind I give the epoxy at least 48 hours to cure, even though it looks and feels ready to cut in about 12.