I will be fitting a Burgess oil bath air cleaner on my Norton engined Trusty, but am not sure how much oil to put in it. I have looked all over and can’t find any minimum or maximum marks anywhere. Also, do you fill the centre chamber or the bit around the outside? Have attached a photo of the base of the cleaner.
There should be a groove pressed into the metal of the base that you have taken the photo of. The groove goes all the way around it- that is the level of oil that you put in. There should be some holes in the centre baffle that let the oil flow through from the outside to the inner ring so that the level is the same in both outer and inner.