Carburetor Jetting on a Harley
This procedure requires minimal mechanical knowledge and simple tools. You will also need a variety of jets.
First remove the bowl off the carburetor by unscrewing four screws at the base of the carburetor. Replace pilot Jet first by unscrewing it from the orifice. Be careful no to strip the head. The head of the jet should be marked with the size of the jet.
Now you can remove the Main Jet from emulsion tube also called brass needle jet holder. Use a flat head screw driver for that.
If you have started out with OEM jet replace Pilot Jet with one size larger. Harley-Davidson CV carburetors usually come with Pilot Jets sizes 40, 42, 45, 48, 50 or more. You should go only one size bigger or you will end up with overly reach idle.
Properly tune your slow and idle jet setting. You don't to worry about replacing Main Jet until this is done. The Main Jet is used at - full throttle range and does not influence idle and midrange performance.
Main Jet sizes are growing in increments of five. Replace your Main Jet with one size higher one.
Avoid Jets that will make your motor run too reach. That will cause some problems down the road.
Now you can reinstall the bowl on the carburetor and install carburetor on the bike.