Ground cable just grounds the tank. The third hose im not sure of. A pic would help. The plugged hose on the carb could be a spare vacum fitting or from removed emissions equipment. Some sounds like that third fitting was for the vapor recovery tank. The vapor recovery tank has a line back to the carb or manifold. Sounds like thats what was removed.

 

 

i have 02 also, just had my tank off last week, i have 2 hoses that connect to the petcock, a vacuum line connected to the back black fitting and the gas line connected to that front brass fitting............also a ground wire on rear mount connected to frame........and a vent hose on the bottom of tank, rear right side, hope this helps

my petcock is a lil different looking than that tho

 

Perhaps your aftermarket teardrop tank has a crossover pipe? To connect both sides when the fuel gets low. That might account for three "fittings" plus the petcock hole. One is a vent line, the other two connect the two sides of the tank. Your description is a bit confusing to me. Can you post up a picture of the bottom of the tank with all the "fittings" showing?

Check your float for sticking, but most important, always turn off the fuel at the petcock when you park your bike. It's not a difficult habit to learn.

Not sure if your bike uses a VOES with ignition, but if it does, there is a vacuum line that goes to the carb fitting on top of the carb near mating surface with manifold seal. Later bikes use a MAP sensor with ignition that mounts on the manifold itself, I think.

Nice looking bike!

John

 

The 1985 I think and on up till fuel injection use a vacuum diaphragm on the petcock. What this does is when bike isn't running there is no vacuum and the diaphragm shuts off the fuel. There should be an outlet for fuel and one for vacuum . What you are seeing for 3rd hole is just a casting hole. If it's leaking at airfilter, the needle is stuck in the carb or float has sunk. Big problem is why petcock hasn't shut off automatically?

 

That tank is gravity feed, 1 tank, no crossover. If it's leaking from the bottom of the carb the floats sticking. I always turn off the petcock because of this.
Drop the float bowl and clean out any debris. Gently so you don't throw the float out of adjustment.

 

 

 

That's your float bowl overflow, and it should not be plugged. It also vents the bowl a little bit. I just run a small hose down below the frame rails to vent/drain it. On my 1991 CA model there was a vacuum valve connected that closed off the overflow when engine was off. I got rid of all that stuff years ago along with the charcoal can.
I know that when I plugged that hose when engine was idling it slowed down a bit, so it does some minor venting as well as providing a way for gas to go if the bowl overflows.
John