Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
I bought one from M&P for the CB250RSA, it didn't fit, incorrect pitch and would have stripped the thread in the sump! When I called M&P all I got was 'oh, you are the first person to have had that problem', really? Like a lot of M&P items advertised as 'fitting your bike' BEWARE! The same applies to a lot of parts sellers on ebay, what they sell is generic and they use the customer as the guinea pig to test parts for them on bikes they have never tested the parts on themselves!
Did you ever find one, if so can you share any links, supplier?
This may give you a source that could get what you want. VW cars for many years have used aluminium sumps, and so have sump bolts that may be of same size and pitch. I've not got samples currently that I can compare to verify. They do seem close though, I'm not due to change the oil on one soon enough to check it for you but they seem quite close to the Honda dimensions. https://www.eurocarparts.com/ecp/p/car-parts/car-body-parts-and-car-exhaust/exhausts/heat-exchanger/?980771141&0&%20&type=shopping&gclid=EAIaIQobChMIxsjwl__C4QIVmK3tCh1SywSXEAQYBCABEgJvc_D_BwEAs an example of whats available in the above link. A standard fit plain and simple sump boot is only about £3 if you feel like getting something to verify the spec prior to committing to spend more on a specialised item.Edit, I searched for "VW sump plug"
Little bit off topic but have you considered one of thesehttp://www.stahlbus.com/products/en/oil-drain-valve/index.phpI've been using one for years now and they are really good, no oil over the exhausts anymore, you can drain straight into an old oil can so no decanting the old oil afterwards with the attendant spill risk AND because you never remove it once fitted no new sealing washers and no chance of stripping the thread out of the sump pan. Ok they ain't dirt cheap but they certainly make changing the oil so much easier, as a one off expense it's one I've never regretted.