Engine reving to full throttle on start

bugger the end a little and tap back in, that's just the bowl vent. I hand an AFB with no air cleaner lose its threaded stud and wedge the secondary open on the freeway. I took foot off gas and it kept accelerating, strange sensation! Killed motor and coasted to stop on side of freeway. You are fortunate that that didnt make its way down further and stick a valve. I dont think that would have made it past the valve at .20 second slowest opening time...anyone?