rschurr wrote:a continuous stream of (foggy) air coming out from underneath the breather tube (but still no oil) Rudy
I had the same copper pipe 'mod' in my square back in 1970 (but with the Marzak gear pump, Morgos hadn't been invented).
After a fairly hard run of 50 miles or more, while sitting at traffic lights, I always had a plume of vapour blowing out of the neoprene breather pipe attached to the copper pipe.
And that was in the summer
It sounds normal to me.
We probably pushed our bikes harder back then - they were just bikes rather than investments. In 1971 I remember Graham Berry peering over my shoulder from the back while we were heading to the Ferry at Harwich saying "What speed are you doing??"
"Bloody Hell - you don't half thrash your square".
It stood up to it with regular maintenance and very frequent oil changes
My avatar shows the late Len Rich in 1970 with the bike I now have - a 1958 Ariel VH