today we're going to do the automatic choke adjustment on this 1969 corvette now one thing to note about automatic chokes for the most part i would say 98 percent of automatic chokes all operate in the same manner it is a simple process but sometimes can be very tedious and trying to adjust to get started we'll go ahead and remove the air cleaner the choke this is a rochester carburetor with the choke adjustment right here this rochester carburetor has three screws for adjustment one two three simply loosen these screws and adjust the choke clockwise for rich counterclockwise for lean clockwise for rich counterclockwise for lean one of the first thing we're going to do is loosen these three screws right here and what this will allow us to do is rotate the choke now in this case this way is lean so counterclockwise is neat clockwise is rich so counterclockwise lean clockwise rich now the way i like to adjust it just where there is just a little bit of a little bit of pressure on the choke right about let's see what we have here that's fully open rich let's go back to lean there we go so just a little bit open right around right around here notice the valve right there it's probably a good position tighten up the three screws and then what we'll do is we'll start the engine and watch the valve open over a period of time so it should be closed right at initial start and then start the open as it warms up and that opened up almost a quarter right off the get-go because it's a little warm today but let's see how it opens up this opening more and more as the engine gets warm and the coil if you'll notice the valve on top the choke valve is pretty much fully open now lastly we'll go ahead and tighten down the screws i think that was about a good adjustment because it started right when i right when i turn the key i'll go ahead and tighten down the screws one note you don't really need to tighten these too much the little spring action right here will be enough to hold the choke in place so just a slight turn without over torquing it is a good adjustment this right here seems to be about the right right place and of course uh each morning you can you can try it out depending on how cold it is outside and in the weather and you can make you know a little minor torques where we go about two notches at a time with your adjustment this right here seems to be right tomorrow i'll give it another shot as a cold start and that's pretty much how you adjust an automatic choke on a rochester 37350 chevy engine i