[header] How to center the jets on su carburetors [title] Loosen the 13/16 " locking nut on the bottom of the jet assembly with a deep well spark plug socket wrench. [title] Get out your 5/8 " socket and unscrew the mixture nut just below it. [title] Pull out the jet and remove the mixture tension spring. 
[title] Replace the mixture nut and the jet. [step] Screw the nut up as far as it will go and push up the jet as far as it will go.