How do you adjust the carbs on a 2008 V Star 650

You can only adjust the mixture for the low running speed from 1000 rpm to about 3000 rpm it's done via a small screw on the side of the carb it should be set at about 1 3/4 turn a out from being fully in.to richen it screw it out more.the higher speed mixture is changed by either changing the main jet size or raising the height of the jet needle by moving a small e clip.

Sounds like it is a throttle cable adjustment on top of that carburetor

Sync carbs ITS ALSO LEAN AIR/FUEL mixture screws if you know what your doing its an easy. Be sure the breather is TIGHT and fuel filter is turned in the right direction IT HAPPENS

Pretty sure your bike has a fuel pump to assist getting fuel to carbs.....very typical to hear the pump click a few times to refill carbs prior to startup....once the carbs fill it stops till the carbs use some fuel......actual the fuel pump is clicking away as needed when the bike is running...you just can no longer hear it over the engine noise.

You need the carb float bowls cleaned out. If water comes out, you will also need to drain the gas tank completely. If that doesn't fix it, you have a punctured carb float or the height is wrong.

this prob happens allways in carburated engines that the car or motorcycle is running lean or rich . because the air - fuel mixture ratio is not right . so you should open the carburator and remove the air filter you will find two screws in the lower front section of your caeburator. you can adjust them by a screw driver until your car is smooth

under the left side of the gas tank you will see i black knob/screw at the end of what looks like a hose. the knob faces the rear of bike. that adjusts the idle. its real easy to find and the only adjustment you can make to the carbs.

Several things come to mind on this. First, rejetting should be done by someone that can do all of the fine tuning also. If the idle mixture screw on the carburetors are still covered, you need to expose them for adjusting. Pull one spark plug and look at the color of the electrode. Black is too rich (too much gas) and white is too lean. You want a lighter brown. Put the plug back in and start the bike. On each cylinder, adjust that idle mixture screw all the way in, being gentle, to the stop. DO NOT OVER TORQUE, YOU JUST WANT TO REACH BOTTOM. Make note of the screw driver orientation and back the screw out 2 turns. This is the starting point. If the bike will no longer idle, adjust the idle screw for about 1000 rpm's. After running the engine for a couple of minutes at idle, do not rev the engine, just shut it off. Pull a spark plug and check the color. Again, you are looking for a light brown. If it is black, turn that carbs mixture screw in 1/2 turn, white, turn out 1/2 turn. Do this for each carb. I know, this is not the quickest way, but it is a sure way of getting the right mixture. It will be time consuming and you might even burn your fingers on the hot plugs.
Now that you have the right mixture, it is time to balance the carbs. I use a Carbtune monometer. Google Carbtune. This is a must to get the bike to run strong and smooth. You will need a service manual for this procedure. Go to Delphi Forums and look up the RSV, Royal Star Venture forum and you will find an electronic version of the service manual there, for free. Hope this helps.
btw, there is not anything around the spark plugs to adjust.