I run 220 main jets on my 72 Roadster, standard 750 engine with 30 mm Mk 1 Concentrics. They are worn but they work OK as long as I coat the throttle slide with some oil every now and then. I want to ditch the original air filter and run with open bellmouths instead. What would be the most sensible jet size to start testing out with ? (I was thinking of buying 230, 240 and 260 for starters...) Do I need to go even bigger ?