The Keihin 150 mains are good. Thanks to Mike Selman of Bellacorse for getting them to me quickly & at a fair price.
The current 1.58mm throttle plate air bleed holes & the custom Keyster 41 pilots are not playing nicely together; with the v-stacks & non-E gas I can get a good idle AFR or a good cruise AFR, but not both. The best compromise has the idle leaner than I want and the cruise richer than I want.
I then changed the 41 pilot jets for Keihin 42 pilot jets, & although the pilot screws don't need to be out as far as with the 41's, the cruise AFR's aren't where I want them. They are in fact a bit richer.
I think I know where this is going next. Smaller air bleed holes in the throttle plates. I'm not sure if I'm going to fill & redrill the existing plates or replace them with spares & drill them fresh.
And I haven't even touched the air cut valve (a/k/a "coasting/decel enricher") yet...
