Geoff that's my Greeves sports twin that Dick Wyler is using it was my second bike (my girlfriends at the time) I re ported it and used it in the 250 class my then girlfriend pranged it searing the headstock off the ally beam it was taken to Thundersley Greeves factory to be repaired and they did it but couldn't believe performance of the engine. They bought it off her for good money and I had loan of a Star maker Greeves 250.. And that bike was my or should say girlfriends bike I knew Dick to talk to in the paddock but wasn't there as I was off riding after my sidecar accident..
Good Ole days..my mate Mick Rodgers guided me through the porting of the engine he was dab hand at twostrokes..