I need some help Identifying a missing part.

I've looked through my repair manual and i can’t find any mention of the part I’m now missing.

My bike is a 1997 KDX 220

I went for a ride this weekend and dropped my bike on its left side. when i picked it up i noticed a little oil had leaked out onto my swing arm near the pivot bolt. On further inspection i found a hole where it looked like a screw? / vent drain? should be. its on the back of the crankcase behind the kick start and above the left kickstart bearing block. You cant see it from the right side of the bike. From the left the veiw is somewhat obstructed by the carb.

What is this hole??????????
What goes in it??????? and what size screw / bolt will fit???



I was planning on going to Hatfield and McCoy next week and need to fix this ASAP..

Thanks
Sean

Thanks.... i believe you are correct. someone else has contacted me with the part# and after looking it up it is a vent drain and tube.

Thanks everyone!!!!

Sean