Silly carb question kz750

So I've got this 750 twin that I've been fiddling with forever and a few years back I replaced the carbs with vm34 carbs prejetted for this engine. It hasnt been all kittens and moonbeams after that but it did start working better. Farm life got busy and the bikes been on the back burner for awhile and I noticed that the slides seem stuck. I can make them move with enough effort but I dont think its meant to be that way so I am curious if these slides are meant to be lubricated in some way as  a matter of regular maintenance or if theres something just not set right maybe that could be causing the slides to stick. 

No on lubrication of slides.

Cables hanging up is very possible.  Also, vacuum leaks causing a high and erratic idle can give the false impression of sticking slides.

If they feel sticky from non use spray some carb cleaner into the throat. The ethanol shit in fuel gets everywhere and turns into a varnish glue if left to dry out. 

Thank you for the replies. Definitely not a vacuum leak since this is an issue when its not running. Its probably been sitting without any attention for about a year now so old fuel gumming stuff up is absolutely possible. I plan to clean stuff up before I start projecting on it again so hopefully that sorts it out. I just wanted to make sure I wasnt overlooking a lube point. Seems like every time I want to work on this I either have spark problems or carb problems. Last time i sorted out the spark issue one of the carbs decided to start puking gas out the overflow. 

Fun times lol. 

I am hopeful however to have it at least in test ridable condition before winters end.