one more gear case question
 

while changing my gear case oil I noticed a plug close to and similiar looking as the drain plug, but it had a spring attached with a small ball bearing. What is this plug for? I removed it thinking it was the drain plug but no oil drained from that plug.

What buggy and engine? What you described sounds like a check valve.

150cc engine / generic Chinese buggy.
 

I'm not sure what name it is.

hmmm..can you post a pic of it?