Vincent, That is extremely privileged information, that not even the most experienced pre war Vin owner knows.........Luckily for you, I spent some time to work it out for myself to get the new "A" twins here set up better........You need an old lower banjo bolt the longer 229/289 type........then drill about a 8mm hole through the base........This way you look in and see what the fuel level is doing........The stock banjo bolt has an issue that it has a cross feed hole........between the hex end and the thread.......The problem here is that if the cross hole is not vertical, the fuel cannot easily make it into the carb base where it draws fuel from with the bolt done up tight........If you cut a series of slots across the bolt thread about 6 of, these slots will let the fuel flow no matter what position the bolt is when it is tight.........The level needs to fill into the carb base (visually through the hole in the dummy bolt) but not high enough to be level with the main jet.........If it is, then the engine will constantly flood........i found on all the float bowls/levels were way too low.......how they are standard........but the correct brass type float bowl, not the later alloy ones, the level was quite close.......i think i simply cut a new slot in the float needle.......this made the float actually hit the top cap.......had to trim a bit off the upper needle guide and trim some off the tickler pin as well.......otherwise the float will flood badly........I don't know why all this seemed so necessary, but I discovered the level was too low, after Rodney came to my place on his bike and at idle speed the engine was only running on the rear cylinder.......when i held the tickler button down briefly, the front cylinder started to fire again........this told me the float level was too low.......i then carried out this same mod to most all of the other twins as well........From memory, the bowls that were made of mazac/alloy, I had to raise the float level about 6 or 7 mm to get the fuel level to flow into the carb base but not too high that is floods easily........Just so you know also, it is critical that you shut the fuel taps off after a run, as a leaking tap can cause the front cylinder to flood badly and it can bypass the piston rings and fill the crankcase with fuel........if you start the engine later, it will overflow the oil tank and make a huge mess.........All good fun........Cheers......Greg.