Triumph Repair: TR6 Carb, needle valve, metal arm

Question
I have a 71 TR6. While driving, the car lost power suddenly and upon opening the hood I noticed fuel pouring from one carb while engine was still running. I have yet to tackle trouble shooting, but perhaps there is some obvious direction you could point me in before I get in over my head

Answer
Float bowl & needle valve.  Pull that carb, remove the bottom "cup", and you'll see the float, and a metal arm resting on a brass fitting.  That fitting is the needle valve.  Unscrew it, clean it, and you should be OK.  You likely have some schmutz in the valve that plugged the valve in the open position.

You'll have to resync the carbs if you remove the carb.  If you can do this while leaving the carb attached to the manifold, all the better.