Younger dog wont leave older dog alone

Question
I have two dogs: Kipper is 5 and I've had him from a puppy-he's altered. Two months ago I adopted Mojo who is approximately one year old from our local shelter-he was altered two months ago. Both are small breed mixes: Kipper is a bichon shih tzu and Mojo might have some shih tzu too but looks identical to a King Charles Cavalier Spaniel. The pair are doing all right together for the most part. They share sleeping arrangements good and food and toys. There are certain chewies that Kipper can be possessive about such as pig ears, soup bones or anything else he finds really "tasty". The problem arises when Mojo tries to play physically with Kipper. (I should tell you that Kipper has a shrill voice). In my opinion Mojo is younger than the guess-timated 1 year (he's only recently grew hair on his groin). Mojo is relentless in wanting to play physical with Kipper and Kipper screams and yelps-often times when Mojo doesn't even has his mouth near him! I had thought Mojo was biting too hard but seen him playing with a friends dog and the pair played fantastically together. Kipper is fine with Mojo to play tug o' war or chase balls together-he just doesn't want Mojo to touch him. I've tried squirting Mojo with water to get him to stop, only works so long. I've tried making a loud noise-once the noise is done Mojo continues. I've tried letting them "figure it out" and it breaks my heart to hear Kipper screeching the way he does. It's to the point where I can't leave them alone together because I'm afraid Mojo will "go after" Kipper and I won't be there to stop it or "protect Kipper". I have to crate Mojo which breaks my heart too. My question is: what training technique can I use to show Mojo it's not okay to play physical with Kipper and how can I stop him when he becomes so focused on using Kipper as his personal squeak toy? I really would like them to be able to be together during the day when I'm at work. Thanks for taking the time to read this!  Oh, and I have had Kipper checked by a vet to ensure he doesn't have something going on with his body.  I also have a video of them playing if it would assist you.  

Answer
Once past 3 years old, many dogs don't want anything to do with puppies, their sharp little teeth, and their biting games.  You need to teach the puppy to leave the older dog alone.  As soon as the puppy starts to focus on the older dog, give it a sharp ''Ah, ah, ah!'' and offer it a chew toy.  This will take many times to become effective.