1. Never embarass them
This should be the last thing you would want to do.. The YIKIT's attitude is just to show that they know more than anyone else, these type of people cannot hide their embarassement and would want to run away from their existing jobs and Team to avoid any more of it. The YIKIT's can be best Team players and also can have lot of knowledge and experience.
2. Throw responsibilities at them
The easiest way to be more effective with a YIKIT is to throw responsibilities at him in such a way that his experiences and knowledge is polished. A YIKIT really may or may not know things but pretend to show it.... making him realise that he doesnt know it can harm so let him polish his skills by making him work in the area he pretends to work keeping in mind that YIKIT's need virtual micromanagement.
3. Turn a YIKIT to a TIKIT or a MIKIT
Step 2 can really turn a YIKIT to Though I Knew it or even Maybe I know it which can be very effective since it will make a YIKIT to go and explore the world. YIKIT's can harm a Team if the YIKIT attitude turns to TITS meaning Thats It ;)
4. Ask Questions that you know and dont know
A YIKIT like to answer everything or show that he is a encyclopedia no matter its a Jack knowledge... I mean Jack of All King of None kinda knowledge... Another way to turn a YIKIT back to normal is throw questions that you have deep knowledge in and where you dont have any knowledge without making him realise about your knowledge in the area.
5. Avoid making statements or giving answers to YIKIT's easily
This is to make sure that the YIKIT doesnt take words from your statements and then make over stories on own, avoid responding first to make the conversations and progress better.
Remember of all the things you need to understand that:
a. YIKIT's are knowledgable
b. YIKIT's are intelligent
c. They have good skills and imagination power
d. They never want to loose
e. They Know what to talk and what not to
I am sure for a success of any Team you need all of these qualities....so YIKIT's been in the Team is important the only thing to take care of is better management of YIKIT's and having a good control over them.