I've been looking at a boat with a 97' 200 efi. It was rebuilt and at times will run ok until 4 k rpm then a alarm. At other times it won't hardly run at all. I did I all I knew to do but couldn't get anywhere. I took it to my mercury dealer and he's telling me the computer is wack and needs to be rebuilt or replaced. So I'm weighing my options. Are used computers hard to come by or should owner have this one rebuilt? Thanks for any insight