The throttle slide on my Mk11 carburettors has the number 2928 imprinted on the bottom and also a number 3, I am running the correct main jets 200's and also the correct pilot jets The machine is even with the throttle stop screw at its lowest setting where it doesn't touch the slider is running at 1200 rpm and I cannot get it any lower even when it is at lowest setting where it doesn't touch the slider it's running at 1200 rpm . The pilot air screw is 2 1/2 times out from full in position, the needle is set in the middle, The only thing I can think of is that the cutout on the slider is too big for standard Road going T140E. I should also point out that the carb rubbers are brand-new and the carburettors have only done 200 miles from new .