Oil pan plug size

[chef]

Before I attack it with a big shifter..anyone able to tell me what  size is the head? 20 mm too small,21mm too big.I assume it's imperial & will require some math.cheers

[stormi]

Ours isn't original, and it's imperial.  I would think that the original should have been metric, as everything else on the bike is?

If you're int eh same boat as we are, it's likely been changed out for a "replacement" when someone stripped the original.  It will be bigger than the original, and hence your oil plug gasket that you got to replace the old one (you did right?) may not fit.  If this is the case, we went to a BWM drain plug gasket.  I can't seem to find the receipt for it right now, or I'd post the part number.  If I come across it, I will post it for you, in case it works for you too.

[interfuse]

Every bike I've had the oil drain bolt was 17 mm....

You could always put a pair of calipers on it to see what size you're dealing with...

[stormi]

K,.. as promised:

Here's what it says on my receipt:
Product # B 07119963252
Description: Gasket Ring "A16x20"

This should change up to a BMW Oil Plug Gasket for something or other. :)  Fits Dita quite well with her oversized plug.  Worth a try.

[chef]

Thanks guys,
Finally got the sucker off after measuring with vernier & scraping my knuckles i resorted to the trusty shifter with no drama.
Its just that whenever i work on the B4 whatever can go wrong usually does & i have visions of the bike falling on top of me & my pregnant wife trying to move it,dont laugh guys,it did slip off the stand once on a ceramic garage floor & it wasnt fun.
 
Looking forward to changing the clutch soon.