OK guys I am not too old not to try something new. my 2020 Comet is intended to take me into the next decade and I doubt that R supplies will get any more numerous. Back in the days of the MCC High Speed Trials at Silverstone when I rode the racer to the meetings there was a garage in Buckinham that kept R on the shelf, alas no more. So I will try some 'oil water' 5W20 especially as on my rebuilt engine the big end has been well run in on a seasons racing (I have flushed everything out with petrol) so here we go onto mineral! (NB my KSS road bike is still on R I have a spare can where the battery went) I have to use R somewhere because if I don't eventually my lathe will suffer as I use old R as my cutting oil )