I have an 8 fitted at present Nigel but may go up to a 9. What I am making sure of doing is planning my route where I don't sit in traffic. I'll stick to riding around the Chalfont/Amersham and Aylesbury areas until the engine is properly run in.
James, I'm using mineral oil, I don't think I'll run this engine on a semi synthetic. As the engine only holds 1.5litres of oil, runs hot and works hard I'll change the oil every 750 miles to give it (and its owner!) an easier life.