Hello gents, just when i thought id experienced every possible fault on the nc30 my carbs started overflowing today! Bikes been stood for a while, and when started with almost empty tank there was no overflowing. Then when filled up the fuel flows continuously and seems to come from the diaphragm bowls and the two 'overflow' pipes that are on the rider side of the carbs. Ive removed them and cleaned & blasted all passageways hoping it will solve this, i dont think any valves were stuck open and the spring needles are all fine. I checked float heights as well and all was more or less fine. Why the hell does fuel get into the diaphragm bowls and why would all 4 carbs be overflowing? Wanted to check with you all before putting them back on.. Cheers

If its comming out of the over-flow pipe it might only just be one carb.. the overflows are connected together.

Your floats might not be sealing.. if you invert the carbs see if you can blow down the fuel pipe, you shouldn't be able to as the float needles should be sealing the carbs.

Nice il try that. Am i correct in assuming the only way it can overflow is if the float valves dont seat?