My vstar 1100 dies when in idle. acceleration is fine. driving, shifting, everything else is fine. when the bike is coming down to idle, it dies

chokes sticking or improper jetting.

Sounds like a bent shift fork. While accelerating you can feel the power cutting in and out quickly. The problem will get worse if you keep pushing 2nd gear till it slips. You can learn where (at what RPM) it wants to jump out and start shifting before it jumps out. The long term fix is opening the transmission and fixing the bent shift fork.

yes

You need to let the bike idle on choke for about 5-10 minutes before taking the choke off to ride it.

sounds like a problem i had with my v star if u can charge it and it starts and runs for a bit then dies again check the rectifier which charges the bike

There are a few quick things to try before cleaning the carbs.

1.Clean your air filter, it may be choking out, trust me a dirty air filter will choke out a bike.
2.Check your spark plugs. If they are black and sooty, change them out. Its quick and less expensive.

I diagnosed a 2001 Roadking Fuel injected. Ran like ****, hardly any throttle response, died at idle.
the customer said he just had it serviced a month ago at the dealer.
I pulled the plugs and they were nasty. The dealer forgot to change out the sparkplugs. It Happens
I Put in a new set of spark plugs and the bike ran like new.
I've fixed a bunch of bikes in the past and this one always stuck in my mind because of the difference in performance.

Try the sparkplugs, i think its more likely to be that than the air filter.

Turn off fuel petcock before you shut down bike. Let idle for a couple minutes. When you restart leave fuel petcock off until it fires. This works for me when its really hot outside. 2007 VSTAR 1100 classic.

It sounds to me that your carbs might be a little gunked up - you mentioned the gas may have been old, so it's possible that the smaller (idle) jets are slightly plugged up. Fresh fuel might do the trick and/or you could try using a fuel system cleaner and water remover. This problem might 'solve itself' with a little time.

As far as the backfire - this might be either from the carb issue or it could be related to that rattle you mentioned - you could have a loose connection at or near the head - this can **** air and cause a backfire.

I hope this helped!

Sounds like it may be drawing air around the intake somewhere. Let it idle and spray around carefully with wd-40 until it speeds up. This will reveal the leak.