jaka is right about the "available temps", but here's what you are looking for: your engine will be O.K. with JB Weld, up to 15% nitro- been using it to make mufflers/ect. for years. I even tried the high temp JB Weld, but found that the regular is just fine. Right now I've got a 4 stroke, and a 2 stroke with JB holding them together (muffler mount/exaust port on the 2 stroke .40 S.T., backplate/crank case on the Magnum .52 4 stroke). No problems

Jetts