Of course I am not responsible for this issue and do not claim that this is exactly what should be done, just saying that this is my way to do it. Everyone is responsible for their own safety bla bla bla.
The project bike stood for several years and the carbs got a bit stuck.
I saw fuel resin marks inside the assembly of the needle/float area, and I saw that it was stuck. I soaked it with WD40 overnight and the next day I made a solution of acetone and clean fuel and soaked the part for a day.
Then rinsed it with dish soap and then with boiling water, when in difficult areas I used an old toothbrush.
The part looks like new.
Of course before the process I disassembled gaskets, because I assume the solution is attacking rubber or paper parts. You should of course purchase a new gasket kit before the process.
I keep the solution in a tight closed can for next use.
Another of course - the stuff is highly flammable and should also not be inhaled, so work in a vented area and keep fire away.
Engine Nr. 529466