Disposition of old gas

[Commissar]

We just took the carbs off of my friends 88 Katana and in that process the "gas" that drained out of it was extremely thick and an orangish/brown color. She still has half a tank and I do not want to start that same fuel back through it when we put it all back together, what is the proper way to get rid of the "gas" left in the tank, and then what to do to the tank before filling it back up. I am assuming it will need to be cleaned somehow, I have no clue what might be sitting in the bottom of it.

[Redstar11]

Just use a catch pan, remove the fuel hose from the carb, and open the petcock. If it is a vacuum petcock, there will be a PRI position that you must set the petcock to. That will hold open the diapraghm allowing fuel to flow. Just let it drain for an hour or two. Once the tank is empty. Pour some fresh gas and seafoam or something in it and swish it around to collect old gas deposits, and drain that mixture too. The tank should be ready for fresh gas then.

Also, if the gas was that bad, the carbs probably need to be cleaned.