Perhaps I am confusing the throttle spring and the pump spring, but still don't get the concept. The shaft and link that I would assume connects to the accelerator, when moved appears to shut the throttle butterfly closed. Most carbs I have seen open the throttle butterflys when when the trottle is pushed.
On my carbs the throttle butterfly is held open normally without any pressure on the throttle shaft linkage. Once you startint to turn the throttle shaft immulating acceleration and resisting the spring pressure, the throttle butterfly closes.
Maybe I'm missing the throttle return springs or something? I just can't figure out why a throttle butterfly would close at you are moving toward WOT.
So I guess I'm still lost....