Missing bolt, probably important?
 

About a week ago I got around to changing out the coolant on my new to me 2002 f4i. I followed the manual and drained the old coolant from the water pump and from the drain bolt in the engine https://www.kappabikes.xyz/honda-cbr-600-f4i/images/1811_112_484.jpg . This drain bolt is is located on the left side of the bike above and next to the left-most header, if your sitting on the bike.

I noticed that the right side of the engine has a threaded hole in the same location, but mine doesn't have a bolt here. The threads are shiny so Im assuming there must have been a bolt here at some time. What is this hole? Should I leave it empty or plug it?

https://www.kappabikes.xyz/honda-cbr...11_112_484.jpg

Manual image of drain bolt

I'm assuming you are talking about the empty hole on the left of the picture below, the coolant drain bolt is on the right side. Its kind of dark but thats from my 01 F4i and I've never had a bolt there either but I bought it with 38,000 KM's on it.

Engine

Yes thats the hole I'm talking about. I guess I'll just ignore it then.