Synchronised carburettors and got another bike, perfect. However fuel consumption increased. Went through following steps:
1. Cleaned carburettors and nozzles (of which two were filled with dirt).
2. Outer spark plugs are black and the inner two normal.
3. Pilot screw is on 2,5 turns instead of 1,5. This controls lower ref region. Is this responsible for fuel consumption? Probably not.
4. Synchronized again.
Q: What things could I try in order to optimize the fuel consumption?