I'm fixing a rider mower for my neighbor, a Kohler CV20S on a 2003 Craftsman DLT3000, and I bought an aftermarket carburetor on Ebay for it (it is the same part number and exactly like the original), and now it runs OK, but the throttle does not begin moving from idle speed till it the throttle is pushed to practically full speed. As you go from minimum throttle forward nothing happens till it practically at full speed. Is that normal? Also, I looked at the carb when it is at full speed and the carburetor butterfly is open only very slightly. Is that normal? I have the mower deck off for cleaning and also sharpening the blades, so I have not mowed with it.