Madfreestyler, the clicking you are hearing is more than likely the cam gear. Every YS I have and I do have a few of them, clicks exactly like your does. If the clicking gets very loud you will notice a loud clicking noise when the engine decelerates. It almost sounds like a buzzing sound. Make sure you are using at least 20% oil in your fuel. To get rid of the noise you will have to purchase a new cam. A friend of mine just replaced a cam in his YS120 this week that had the exact same noise you are talking about. The noise is now gone and the cam was $30.00. If the engine is still under warranty send it to YS for servicing and a free cam.

Good luck. Bob