Since we are all so far flung, (and half a bubble off plumb) I propose that be the test. A proper shot glass on the top tube behind the tank. Half filled with water. (For now 'cause these things never end well and you will want a drink)
Exactly one half once. No more and no less. Gentleman's honor. Or in our case, insert joke here.
Idle to full revs! Gentleman, submit your vids!