Fuel leaking from air box drain

My bike starts dripping fuel form the air box drain after about 5 min of being stuck in traffic and sitting at idle. Any reason why? I believe that it is because my carbs need synced. I just recently put a modified exhaust on my bike. I went from a 4 into 1, to a 4 into 2. I know the carbs are good because I had them cleaned by an expert and it didn't do this before I changed the exhaust.

Yes I said it "stuck" in traffic. The cops on base and the rest of the base populous get there panties in bunch when you use a bike like a bike. So on base I get stuck with traffic, but as soon as I am free of the gate it is game on.

I am pretty sure I know why this is happening. I just wanted some 2nd opinions. Thanks and take it easy

 

They may have been cleaned but it sounds like you have a float valve not seating, or the float height on one or more carbs incorrectly adjusted.

Before you pull the carbs check the float level on all carbs with the clear tube method so you know where your at when you get the carbs pulled to check/set float heights.

 

You could benefit from an inline paper filter.
A tiny flake of rust or dust wedges in the needle and seat, letting a float bowl flood. Some full throttle driving (game on!!) will flush it, the problem goes away until the next tiny piece of crud comes along.

Meanwhile these dirt particles migrate to your idle circuit.
Don't buy a screen-type filter, as you already have one.
(and +1 to the above)

 

I will give the paper filter a try.

Thanks