Hi, I’ve had this problem with my GT 550 for a while, and I really need to sort it out. Ever since I dropped the bike (tried to ride off with the disc lock on - duhh!) the carbs have been flooding petrol and filling up my air filter with petrol. I took it to the garage a while back, and they replaced 2 diaphragms, although they never really got the synchronisation sorted. But then a short while later the prblem came back. I had taken the float bowl off (I haven’t got a garage or anything) because I figured the floats might be stuck, but it looked ok. (Can’t really tell, I’m not a mechanic). I think it must be the floats, right? Or the needle? Sounds crazy, but maybe the floats are filling up with petrol and sinking? I think it’s just carb no.1. I am going to do this myself, and even buy one of those carb synchronising tools to measure the air pressure. I have heard it’s a really tricky thing to do. Is it that tricky? Ps my carbs are the Keihin CV ones, it’s a 1990 GT 550 G4. Peter