pearl;

Return spings at carbs are supposed to return jets to the normal, unchoked, position when you push the control back in....but if your linkages and cables are lubed so well and move so nicely that the engine vibration alone is enough to vibrate them back under the tension of the jet return springs...consider yourself lucky...it means, you never have to worry about forgeting to turn the choke OFF! Sowherezaproblem?

Cheers