2002 Vulcan 1500 Classic has fuel pouring from the overflow tube that leads from the carb and routes down by the battery.

Many bikes have a fuel overflow at the fill opening at the tank. So excess fuel can drain to the ground. This is done with a tube that comes from the rear of the tank (close to the seat) and routes down under the frame to the ground. If that tube is routed to your battery box then you have a safety issue. Make sure you do not have this drain tube/hose routed to your battery box. I am sure you don't want a fire under your seat.

check the routing of the overflow pipe from the tank for leaks a photo would help

the crank case vent is 100% blocked.

sounds like carb, is airfilter set up ok, it can act as an air restrictor to match the jetting

TO ALL VN1500 OWNERS....This once happen to me,
I went to the garage to start the bike "Nothing ""The first thing is the lights are bright but no turning over,Next you think the solenoid is kaput but the answer was very simple and the fix takes 30 seconds..
Do not take the bike to bits looking for other problems and look at the clutch leaver and you will see some wires going into a plastic shroud going into the switch in the clutch leaver, Make sure this has not popped out if its connection as it some times may do after a few years due to constant turning on the handlebars,
When this is not connected you will have a bike that will not fire up but comes alive and you will hear a clicking noise but this is from the engine carb area and every function of the bike will work but it will not turn over, Worth looking at and saves sixteen quid for a starter unit you never needed.

Only if they are a little on the long side or are not routed correctly.

u need clymer manuals for both bikes--library has a vehicle troublshoot section also

Fuel bowl needle is bad and not seating properly to seal the bowl when enough fuel has entered, thus it overflows out of the vent tubes.

dear vulcan owner i had the same problem on my 96 vulcan classic found out that the carb is set to lean from the factory solved the problem by rejetting the carb. i also installed a set of aftermarket pipes made a world of diff to the power out put

Yes, it sounds EXACTLY like a stuck float. You may be able to fix it yourself depending on how accessable the offending carburetor is. Quite often you can free up a stuck float by setting up a bit of vibration. Give this a try > tap the side of the carb repeatedly using the plasitc end of a screwdriver. You are not looking to hammer the thing to death, just create minor shocks. The shocks / vibration will often free up a stuck float. Please rate this solution and let me know if all went well.