Super C - Carter UT Carb Rebuild in Technical IH Talk Posted July 13 You will be fine ,trust us ,you can rebuild that carburetor , I took one look at it and it will be fine. I suggest you go to mikes carburetor for kits and advice . https://www.carburetor-parts.com/ihc-carburetor-rebuild-kits also trust McDonald carburetor for parts kits and advice also.https://www.mcdonaldcarb.com/category_s/378.htm your explanation tells me you must rebush the throttle shaft bore in the upper carburetor so it has minimum clearance for free rotation so to maintain maximum carburetor adjustment for maximum performance . Sounds like this tractor has had a hard life. Things need to change for the better. ask more questions .