Knocking / Tapping in Engine (Engine Area) at Idle

I purchased a 2009 Gator 620i with 300 hours on it a few days ago. I discovered today that there is a loud knocking / tapping noise in the engine or area of the engine at idle. The noise tends to either go away or is masked by the louder noise of the engine revving when I accelerate. The gator runs and operates fine. The unit has a Kawasaki engine.

Any thoughts on the source of the knocking or if this is normal for this engine/model?