Can't get bike to start/idle

[Farva19]

Ok, this bike is new to me. I bought it as a project bike, its an 82 gs1100gk. when i took the carbs apart there was stuff stripped out and jets clogged and everything else, so i took em to a shop and they rebuilt and dipped em. supposedly they have it set up so i just put em on and the bike will start. I have checked my spark, it seems like im getting fuel and there is compression.... i am lost, i put my hand over the back side of the carbs when it was cranking and it sucked my hand in and it started... then it died. I hope this makes sense to some1 but i am so high on gas fumes right now i dont think im making sense...

[mike_of_bbg]

If you're putting your hand over the back side of the carbs, then you probably don't have your airbox installed and tight. The carbs depend upon that restriction to help induce vacuum and pull fuel into the airstream.

[Farva19]

well i went back out to the garage and tried putting the airbox back on.... nothing.

[mike_of_bbg]

Obviously you're running lean.

Did you put the airbox back on WITH the air filter? Check the condition of everything: make sure the airbox boots have no cracks. Did you check the o-rings to ensure they are in good shape? If you have any air leaks at all from a stock system, you will have trouble running.

http://cycleorings.com/intake.html

Are you putting on the choke when you're trying to start?

How far out are your idle screws?

Since you didn't clean your own carbs, you will get suggestions to clean them yourselves: and I would do that. Did they replace the jets and other internal parts with OEM parts or those from the commonly-available cheap rebuild kits? The latter are reputed to frequently be of much poorer quality/tolerances than the original stock parts. The stock parts rarely ever go bad; just need cleaning is all.

Also, have you checked/adjusted your valve clearances yet?