I like the slide air port hole size (#39WG), there is no need to go larger IMO, at least with the FZ1 springs.
The motor had a slightly rich range at very light throttle from 2.5k - 3k RPM; I suspected it might be float height, so I dropped the fuel level another 1 mm or so.
I'm not a fan of the "measure the float height with the carbs pulled" method, as when the carbs are reinstalled there is no guarantee that the actual fuel level will be where you want it. I therefore prefere the "sight tube" method that shows the actual fuel level in the float bowl, with the carbs connected.
The starboard side adjustment was a piece of cake. The port side, however, was an absolute ******, though. I think the port side can be tweaked another half-mm.
Anyway, my theory was correct & the issue resolved.
The motor has a great balance of performance & economy; it is a kitten at low-rpm light throttle, a lap-cat at cruise, & a tiger at WOT. It is responsive, smooth & strong.
When I get some time I'll take it for a dyno run to satisfy my curiosity. I have a pretty good idea what the numbers are likely to be. That said, so what, the driveabilty is excellent & that's what I'm after.
