How do i adjust the carb for a lean idle and a rich throttle on a 97' harley sportster 1200

This is done by changing the main jet for full throttle adjustments, adjusting the metering rod (jet needle) clip position for midrange and the pilot (slow) jet for idle and just off idle. There is also usually a mixture screw on the carb somewhere, location depending on which carb, that will also control the low speed mixture. Why are you wanting to lean the jetting. If a carb becomes rich for some reason the solution would be to fix the problem not band-aid it with leaner jetting.

If the carb is adjusted correctly, the engine will not idle without the choke when cold. I will usually take at least 3 to 5 miles of riding to get the engine warm enough to idle by itself without the choke. If your bike is a full operating temperature, it should idle at about 1000 RPM. If it's idling higher than this, you need to slow it down a bit.

Remove the air filter cover and look at the top right side of the carb. You'll see a screw there . This is the throttle stop screw. Turn the screw counterclockwise to lower the idle speed to 1000 RPM or so. Blip the throttle and let it settle back to idle. Reset it if necessary. Once set, put the air cleaner cover hand on.

It sounds like you may have a vacuum leak on the front cylinder where the intake manifold bolts to the front head. This will cause the rear cylinder to run a bit richer than the front and the lean mixture on the front cylinder will make it spit back through the carb occasionally.

Now, you didn't say what type of carb you're running. If the carb has been changed to an S&S carb, the accelerator pump is adjusted too rich. Go to this site, download the installation instructions, and read the part about adjusting the accelerator pump.
http://www.sscycle.com/instructions/instructionslist.php?x_cat=1

Click on "download" for the Super E Super G carb. Instruction sheet 51-1012

Good Luck
Steve

Take your air cleaner outer cover off. Look at the top of the carb with the large cap on it. Just to the right (towards the front of the bike) is a screw. This is the throttle stop screw. Turn the screw slightly clockwise to increase the idle speed.

Good luck
Steve

Take the air cleaner cover and the air filter off the carb and ride the bike in the range that you are experiencing the problem. If it runs better with the air filter off, your carb is probably jetted too rich on the main jet. If it runs worse, it' probably too lean.

If you crank the throttle wide open in high gear the bike starts to pull, now, back off just a bit. If it pulls better when you back off just a bit, the carb is lean.

Carb or EFI? Need to know before an answer can be given.

It could be any number of things but I would tend to think that it's something to do with the carburetor. It could be something as simple as it's idled too low. The idle speed should be about a thousand RPMs or so.

Your bike also came from the factory jetted extremely lean. A "jet kit' may help the problem in that it will richen the mixture up just a bit making the transition from the idle circuit to the midrange circuit smoother.

Next, you may have a problem with the accelerator pump on your carb. If the pump is not working correctly. Remove the air filter cover and element so that you can see into the carb. With the engine NOT running, crank the throttle to wide open position while looking into the carb. You should see a stream of fuel being squirted into the carb out of a brass nozzle in the throat of the carb. If you don't see this, you need to have the carb serviced.

Could be an issue with a spring on the carb.

Too rich or too lean condition will only occur on that model if the o2 sensor,or computer is bad.(If it runs,You can rule out the computer)

It has EFI system and the computer controls the mixture constantly adjusting it.

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