'83 750 maxim rough start and idle

I have an '83 750 midnight maxim. It hasn't been started in over 15 years. I changed the oil, put in some new plugs and was able to get the engine to turn over and then start up with lots of choke and throttle. I tried Seafoam in through the airbox to see if I could get the carbs to run better. Lots of smoke and still rough running. I took the carbs off and cleaned them. The carbs are reinstalled but I am still having rough starting and idling. I looked at the plugs and cylinder 1&2 have dry carbon on them. The engine almost sounds like one cylinder isn't catching. Is there a simple way to figure this out?
I made a short clip with the noise. I hope this link works.

 

You can't just pop the carbs off of a bike that's been siting, do a quick clean, and expect all to be well.

There is much to do before she'll be a safe and reliable ride again.

Read This First to get an overview of what needs to be looked at.

Then take the carbs to church as a starting point.

IN THE CHURCH OF CLEAN

 

Thanks. I did spend 2 days on the church of clean on my carbs. I first want to make sure the engine starts and runs on it's own before I get into the rest of the bike.

 

All of the following was done?
Full teardown, soak, all passages confirmed clear using compressed air or spray cleaner, throttle shaft seals replaced, float needles replaced, float levels wet-set, idle mixture o-rings replaced, idle mixture screws set at 2 1/2 turns from a soft-seat, bench synch performed, petcock confirmed to work, petcock set to prime before attempting the first startup?

I want to be clear this is not a criticism; I just want to know what baseline we're dealing with to help diagnosis.

 

Time for confession at the Church of Clean. I didn't take the bodies off the rack, so no bench sync, nor replace any parts. Nothing was worn or torn. I did overlook about the idle mixture screw being 2.5 turns from soft-seat. Looks like I will be pulling them out again. Just curious if you were able to hear the clip and if so, do you think it is missing and thus a carb issue?

 

The clip had bad audio, and was too short to be useful.

You can't be sure that nothing was worn or torn unless you break the rack. 6/8 of the throttle shaft seals can't be seen unless the rack is broken, and they tend to harden and crack after 20 years, even when just sitting. The idle mixture screw o-rings have the same issue. Age kills rubber parts.