vacuum problem on my 85 vf500f

bike ran ok before i took off the carbs to clean them, i put the carbs back on ,synced them them out of nowhere when i rev the engine it slowly goes back down. i sprayed carb cleaner around the carburetor boots and it revs up and burns gray smoke from the exhaust. im thinking that i have a bad seal on the carb boots. idk? somebody please help me