Motorcycle Repair: 1100 goldwing 1980, air fuel mixture, vavle

Question
bike sat idle 2 years .cleaned carbs. fresh gas all the normal stuff after setting up.#2cyl will not hit unless i take the vaccum test screw out. will hit on#2cyl then. have cleaned air  jet several times.how dose air cut off
vavle and controlls it.#2plug  has black carbon on it
thanks for any help and any other info on restarting old bike. oh compression is in 120"s

Answer
Ricky, the #2 cylinder is getting way too much fuel.  I'd guess the float level is too high.  When you pull the screw it leans the air fuel mixture and it fires.  The air shut off only shuts the fuel off when there's high vacuum when the engine is decellerating.  

Regards
Rich