The A3 is probably too hot for a TT 46 Pro as Jan mentioned but that's not a hard and fast fact as I have an older Tower Hobbies 46 that won't run on anything colder than an OS A3 and 15%. It's an awesome running piece, it just has to have it's A3 and 15%. We have some folks at our field with Evolution engines that won't run right without an A3 in them either. Go figure.