Friend is mine was given this bike which hasn't been started in many years.  Removed the gas tank and it's dry.  One carb drain let out some "normal" smelling gas, but another one a little smelly gas, like really old.  I know there's a long list, but what do you guys recommend I check before trying to start it?  I don't want to remove and clean/rebuild the carbs if I can help it.

Friend is mine was given this bike which hasn't been started in many years.  Removed the gas tank and it's dry.  One carb drain let out some "normal" smelling gas, but another one a little smelly gas, like really old.  I know there's a long list, but what do you guys recommend I check before trying to start it?  I don't want to remove and clean/rebuild the carbs if I can help it.

We all look for the quick route to "does it run?"

Normal smelling fuel in one bowl is an indication the petcock leaks ever so slightly, assuming the smell is gas as you say the tank was dry.

Given that, prepare for fuel running everywhere once you fill and open the spigot. You may find it fruitful (and easy) if you remove the tank entirely, plug the one vacuum line to the petcock, then fill the carbs with fresh fuel using a 12-50cc syringe from your farm/ranch store. If it starts, cool, go from there. Typically this would be:

Fresh hoses all around warranted, fresh fluids too. Don't neglect rear pumpkin and coolant.
New sparkler plugs may be warranted.
Clean tank with fresh fuel (swish and spit, again), inspect petcock and petcock strainer, replace/repair as needed.
Flush carbs, plan on rebuilding them.
Lube all wear points. Lube again, then check if you lubed all the wear points.

Rick

How and where was it stored?

There is a very high likelihood that you'll need to redo the carbs and a lot more. Read up on hydrolocks before doing anything.

But you can try run/drain some clean gas through the carbs to try and clean the bowls. Ultimately, if the passages are clogged you will need to dismantle them. You should put some gas in the tank, swish and clean that out first. The fuel filter should be checked and cleaned. Take the spark plugs out and see inside. I normally spray some fogging oil in the plug holes and turn the engine w/o the plugs to lube the cylinders since they are dry.

Change all fluids and check all rubber and lube all required friction points. Are you brakes frozen?

You have a lot of work. Don't just start the bike! Plan for a front to back check/clean/repair/replace, etc.

I wouldn't even dream of starting it without going 'COMPLETELY' through the fuel system, not to mention the other stuff you should do.  I would get the carbs rebuilt and install a new petcock or at least rebuild that as well.

Hydraulics will need to be flushed then flushed again a year or two later as the new brake fluid slowly will etch away deposits that you can't clean now. I bought a 2004 with 11K miles 3 years ago and promptly flushed brake and clutch systems only to have the clutch slave start sticking 3 years later.
Tires - never trust tires older than 5 years regardless of how much tread is left. The date of manufacture is stamped on the sidewall. Buy new tires if the current tires are 5 years or older.