97 yamaha 600r at idle the rpms slowly drop insted of a sharp drop when throttle is let off thinking the jets maybe stopped up or has a fuel return issue, or the carbs are not in sync. thanks

SOURCE: Cleaning Carb Jets

not to a trained ear also go by rpm and spark plug color

NOTE: use copper wire to clean jets, sync is just thottles are same position as all carb's just leave them adjustments alone will be fine if are out use a 1/8 drill an place in between piston/butterfly to carb bore to sync/calibrate

better use a manometer for adjusting screws

depends on condition of org parts

worn = richer running

new = lean an clean

also if changed the exhaust system need to
re-calibrate carbs for max performance

SOURCE: 92 yamaha fzr 600r clutch lever sticks and clutch slips

Sounds like the bike has been doing wheeles and burnouts. As the clutch plates wear the cable needs adjusting. You have reached the end of the actuating cam. New plates are your best bet.

SOURCE: how to clean carbs on a 92 ninja 600R ?

TRY THIS SITE BUDDY http://knol.google.com/k/evan/how-to-clean-a-motorcycle-carburetor/1cxrwhqe214sz/2#

SOURCE: Carb Sync on an 01 YZF 600R

Here is a diagram showing the tubes you connect your vacuum gauges to.
http://216.37.204.203/Yamaha_OEM/YamahaMC.asp?Type=13&A=326&B=11
The YZF600R is carbureted, so I do not know what you mean by throttle body adjustments.
Synchronizing carburetors means adjusting the throttle plates (butterflies) so that all cylinders are drawing the same amount of vacuum.
Here is a diagram of the carbs. Screw #31 is the screw used to change the sync.
http://216.37.204.203/Yamaha_OEM/YamahaMC.asp?Type=13&A=326&B=13
Remember one other key point, all carbs are sync'ed to the #3 carb. You cannot change the vacuum (directly) on #3. It is usually best to start by syncing #2 to #3, then #4, then #1. Changing #2 can affect the sync on #1 so you definitely want to do 1 after 2 no matter what. If you have one cylinder WAY out of sync, that would be an exception to the previous rule where you would want to attempt to get that cylinder in the ball park of the others before fine tuning each cylinder.
Syncing the carbs is an alternating process between adjusting the vacuum then adjusting the idle. If they were out of sync, bringing them back in, or even getting close, can cause the idle to raise because the engine isn't fighting itself anymore. Always keep the engine idling @ 1100 rpm's while syncing.

SOURCE: won't idle without choke, turn throttle boggs out

have u checked the float hight on the carburator? also make sure ur choke curcuit i clean and free of dirt