Hi Karloss. The oil pump O'ring seal you talk about is located at the back where it fits in the casing and fits externally round the pump casting. Where the o ring is fitted the driving shaft comes out of the pump and there is an internal seal to seal between the pump and the drive shaft. If this se...

ok update time... £1.89 seal from simply bearings 9x16x4 (not the 9.5x16x4 as standard) 9mm seal has a good tolerance range and will do the job. I fitted the new seal and lubed it before pushing it on the drive shaft. Tested and works a treat. pump removed from shaft and refitted without the need to...

thanks ill have another search

Hi everyone, New to the site and now the proud owner of a mk2 250. As ive never owned one of these b4 im still finding my feet around it and what is right and wrong. after buying the bike I topped up the 2 stroke tank, drained and refilled the gear oil (my own piece of mind) and thought everything w...