Sea foam is awesome for really hot engines like V-twin motorcycle engines... Thats what I used it for mostly. I also use it as a gas additive every few tanks in my other cars to clean the injectors. I have not used it in my GN yet.
It can be used as an oil additive, and it works VERY well to get rid of carbon build up. You DO NOT have to flush the engine out, or change the oil after use, but I still do anyways just because I usually need to do it. Now I dont have a can here, but I think it says that it is safe for all vehicles including diesel and turbo cars, but Im not sure. Im really leary of putting anything foreign through my turbo.
All in all is is good stuff, and it can also be used as a fuel stabilizer.