Hi Peter, In my limited experience checking the oil in any single is pretty crucial. With an XBR, take it for a short run, say 2 or 3 miles, then let it sit at tick over for 2 to 3 minutes, approx. 1200 revs. then switch off, and check oil. I have tried just running them from cold for a few minutes in the shed and then checking oil. you get a totally inaccurate reading.
Cheers
Tim