Xj550 revs sticking high

Hello guys hope you can help
My yam xj550 can stick in revs , so I turn her over and she idels then I can rev her and she will fly up as normal but come back down very very slow or sometime stick for a little bit . Can anyone advise me on what I should check and look at . Thank you

 

choke off?

first make sure throttle cable is lubed. throttke handle is clean and lubricated with graphite . and cable is adjusted properly.
is linkage binding clean that area too.

make sure the throttle cable is routed properly with no odd bends.
clamps on carbs installed correctly?

have you bench synced the carbs? if you had them off.
done a running sync?

time to check for vacuum leaks nipples all covered ? how do your carb boots look

 

Throttle cable all good and choke off . Vac leak is a possibility as the nipples seam very lose and boots don’t look (as tight) as the should . The boots are new so I’ll try getting new clips for the boots and nipples and try that , thank you for your comment much appreciated