Did the swap to 14T front sprocket recently and noticed two things:
1. The bike is A LOT nicer to ride (IMO).
2. The fuel economy improved!
Fuel consumption from most recent fills in chronological order (oldest first):
5.28L/100km (commuting)
5.35L/100km (commuting)
5.36L/100km (commuting)
14T sprocket fitted
5.01L/100km (commuting)
4.94L/100km (commuting)
4.41L/100km (very slow twisties riding - I am a noob)
The only explanation I can think of is that I am using higher gears more frequently now.
it might be that at the new rpm and load point you're mostly using now the main and/or offset mapping fuelling is better. or it has more spark advance (entirely likely, possibly quite a lot more).
generally engines are more efficient with higher load meaning higher throttle openings, ie, same load at lower rpm. so it's somewhat non sensical that it uses less fuel, but the first part is theory based on everything else being ideal. it's the practical reality of the everything else part that is usually the issue.
I found I drastically lost fuel economy after my 14T...
...because it was so much more enjoyable to ride I wanted to flog it much more frequently [laugh]