So the 500 engine is all torn down (no pics as at Jack's - and again huge thanks to him for all his work), curly alloy swarf has been found and a scored up bush....not sure what's caused it yet but it's certainly having a re-grind new bush, shells and bearings!
Anyway as for the question - I'm running an open primary - does anyone know how the seal on the end of the crank works - does it stop oil both ways or just one? I'm planning on swapping to belt drive so any advice gratefully received - email to the usual address.
Cheers and Beers!