I guess its to improve atomization of the fuel until engine is fully warmed up. My 51 flathead has one,that tells me it has little to do with emissions. Mine is wired open as it likes to stick.
That's it exactly. Once warmed up, it's actually of no benefit. Especially on a performance build that needs a cooler incoming air charge. I've never needed a choke, for example. On anything. Nuthin. Nada. Zilch. Would it speed up gettin on the road? Maybe, but if I'm ever in "THAT BIG" a hurry, somethin's wrong.
