RobH wrote:It's a separate bearing, seal & spacer 42312KV3700, which is discontinued
I have seen some on auction sites
https://www.cmsnl.com/honda-nsr250r2-1988-j-japan_model49608/partslist/0133.html#.WykHbWBFzZE

Hi Rob,

Yes you're right. The part was so corroded being the original that it appeared to be one.

Thanks.