Today I tested the clockwork racing engines modified werks B5 pro fitted with a novarossi carby using a 8mm venturi, 0.4mm idle gap and the engine was temping at 210f, I had a complete tank run at the pace shown on this video and the tank ran empty at 12.26 ...... really liking the nova carby which has given me a wider tuning window in my book and lots of venuri options too.