Thank you all very much for that info ,Im now a little wiser
,why I asked is that it does stand out ,exceptionally so , amazing what an old school air cooled motor could do ,I have set myself a tall mountain to climb in challenging the A/BF & APS/BF 1350 records as the A/BF 1650 record is so much softer .
Any other pics and info would be much appreciated
Gary