The oil mist from my breather just seems to end up all over the frame tube just below it. It does seem rather odd that the plunger bikes, where the gearbox sprocket would be closer to the breather, had the pipe whereas it was deleted on the s/a machines.
Hi Ian
Mine was irritatingly messy too. Easy to mistake excess breather oil for a leaky chaincase. The cork seal on the timing side must have no play. I had not realised until this year just how critical this seal is to minimising 'misting' from the breather. I fitted a paper gasket under the cork disk to take up the thou or 2 of slack and the engine became much cleaner.
Sorry if you have attended to this point already. Cannot agree more about the hamfisted corrupting the efforts of the designers.
I wonder if BSA realised after the plunger bikes that the breather in a well sorted engine is unlikely to be a significant souce of oil escape, so saved a few pennies on the tube.
Cheers
Mike