So just to be clear (and I'm still learning), If I run just primaries, the air/fuel mixture has a certain air/fuel ratio. If I open the secondaries, these will have the same air/fuel ratio if the jets are the same as the primaries, no? The only difference being twice the air and twice the fuel, but same ratio. So how would that run lean if I were just on primaries if the air/fuel ratio is the same whether I'm running primaries or secondaries.
Yes, you are correct. You can maintain the proper mixture either way, you would just run out of carb earlier. Sorry, was a poor attempt at humor, hence the smiley, since you have so much engine.