would out of sync carburetors cause my bike to loose Rpms while idling and die?

Answer 1

The reason carbs have to be synchronized so often, is because each cylinder wares out at a different rate than the others (piston & rings, valve adjustment, valve leakage due to carbon build up).
Synchronizing the carbs is actually adjusting each carb's idle, to get each cylinder idling at the same RPM as the others.
So yes, carbs out of sync could cause the engine to die.
Engines with a lot of miles (worn out, in need of a rebuild) will need the idle set higher than normal to to stay running.
Clean the carbs and adjust the valves before synchronizing the carbs.

Answer 2

I guess it could, but my way of thinking is how much fuel does it take for a bike to idle. I did have a brother-in-law that had a Honda 500cc in-line four. He purchased the set of four gauges to do the job and did it himself. I'm guessing to have a shop do it would be cheaper than purchasing the gauges.
Before I did anything with the carburetors I'd check for air or maybe vacuum leaks. You could check to see if your carburetors are sucking air at the intake manifold by spraying WD 40 at the back of the carb where it mounts to the intake manifold, and where the intake manifold mounts to the head. Spray this at these points while the bike is idling and see if the idle picks up then you spray the WD 40. If the gaskets are all good and the bolts are tight and you're not sucking air. Might be out of sync problem. Could be dirty carbs. Idle jet clogged. Might try putting some Chemtol B13 in your gas take and spray some choke cleaner in the carburetor throats while the bike is running. Or get a rebuild kit and rebuild them or have someone.

Answer 3

If you're talking about one of those four cylinder jobs, or even two with two carbs, yes, out of sync carbs will tend to do just that.
You usually need a manifold to syncronize dual or quad carbs. I had a Honda 750 k, model, four cyl. in line and it was very touchy when it came to the carbs, so much so I purchased the mercury manifold to set them as it was more accurate than the dial type.

Answer 4

Yes, or the carbs might just need cleaning.