A cheap and easy way to make sure the cylinders are in Balance
It doesn't hurt to do this each time you do something to the carbs and only takes a few minutes
Click here for instructions on making a sync tool.
Hook up Location
Valves must be properly adjusted. Warm the bike up, go for a ride.
Look between the cylinders (from the left side of the bike) you'll see a plugged hose piece coming out of a intake manifold under the carb, and a hose going to the AIS, remove them. Hook the carb stick tubing up to each manifold.
Start the bike. Adjust the screw between the carbs to try to get the two tubes of mercury to be close to the same height. They jump around a bit. Then lightly blip the throttle, and adjust again. You may have to do this a couple of times. Don't rev the bike to high or it will ingest the mercury, which doesn't burn. If you have a stand or get a buddy to hold the bike straight up, hang the mercury sticks off the left handle bar. Don't burn your hands. Some of the mercury sticks allow you to hook up the hoses while the bike is cold (plugs or shut off valves), then go ride. Then hook the sticks to the hoses Only takes a couple of minutes to adjust. Good luck.
The 650 is not a Harley and the idle should be set about 1250rpm