Just as a test, you can take a small screw with it's nut and put in the secondary's slot so that the primary lever immediately opens the secondaries with the primaries. This will likely be too much, too soon if you open it up at low engine speed. But you will be able to tell as the engine revs up whether it runs better than before.

Again, this is just a test to see if you can tell a difference with the secondaries known to be opening.