No. The carbs should only be synched when you know your valves are correct, otherwise it won't help. Trying to synch them by ear will most likely make a bad situation worse.
You might want to reconstruct your tool, but this time route the hoses between two pieces of wood that you are pinching in the jaws of a vise. Close the vise so the tubes are completely constricted. Hook it up to the bike and start the motor. Then slightly open the vise until the water just barely moves. Don't know if this will work - water is so much lighter than mercury. Even the tubes on my mercury tool have plugs that constrict the tubes to about a 1 mm opening.
GM top engine cleaner will remove carbon deposits from the combustion chamber & back of the intake valves. If you go this way, follow the directions, and avoid hydraulic lock. Oh, and do it on a day when the wind is blowing towards your least favorite neighbor...
Z., If it were me I think I'd put the bike in the shop for a valve check & synch Couple hundred bucks, but it's winter...