4K? Thats a smoking deal for a Stoker. Look it over very careful and take a rubber mallet with you. Tap on transom and bottom and listen for changes in sound. If it has really noticeable sounds it could be wet or seperated. Thats not a good thing. Good luck and post pics!!
PS: I would worry more about the boat than the motor as mercs are very easy to rebuild. I do mine all the time.