LH Engine Case Mystery

[moonpup]

Yesterday while I was once again sorting through the box of engine parts that came with my bikes, I noticed that the LH engine casing had a hole near the bottom right side corner. Curious, I took a look at the case on the other bike to see if there was a rubber plug or something that was suppose to fit there and there was none....... no plug nor was there even a hole?

I then checked out covers on eBay and found one with and one without the hole. Below, I've attached pic's of the eBay covers.  BTW, the parts manual shows no hole.

Since the hole isn't a factory thing, I'm now curious as to how or why it got there, especially now that I've seen 2 covers with identical holes. Were they drilled there on purpose to help facilitate some kind of adjustment or is something known to break and punch a hole in that general area?

[ziggy stardust]

I'm sure I've read about this somwhere, I think it's mentioned in the BS service sheets.

Just had a look, no it's not what I thought, it's a similar hole but in the R/H cover.

Z

[coxy]

speed hole makes it go faster

[reed]

Mike,
Check the left side lower casing plug you will see its in the middle, its for removing the fork guide pin  part number 2113-9000.
That's what your shift fork goes through that pin, see page 22 in the parts book, if you need to remove the shift fork you split
The crank case then there is a plate and a screw on the right side that you remove, then you push the fork guide pin out to
The other side that's when the plug comes out,now if its left out the pin can come out on the left side and could make a hole in that casing etc just idea...
Thanks.
Steve.