I have an International Farmall "A" with a TSX 157 carb. Last used a few months ago and needed to change the head gasket. On start up the engine would only start and run at 90% choked. I have rebuit this carb a few times with great success. I disassembled the carb, blew through all the jets, checked the float for proper float level and reassembled. On start up the engine ran the same. I tried adjusting the idle mixture and this did not help. Any suggestions, help.