Don't worry about airbus, nothing before carbs will cause you these problems. Rubber boots between carbs and engine though, should be tight with no leaks. You'll want to disassemble carbs down to individual components for thorough cleaning of each part:
Take apart emulsion tube into constituent parts: main jet, holder, needle jet collar. Note how needle-jet collar is oriented so you can re-assemble later same way. Unscrew pilot jet being careful to not lose spring, washer and O-ring. Might as well replace O-ring, float-bowl seals and float-valves.
Then use soft copper wire of various diameters to poke through all tiny little orifices in all parts. Some people use guitar string to floss out secret passages in carburetor body. Blow compressed air through all circuits and verify you've got air coming out other end.
Finally, dunk all parts into 50/50 mix of acetone/ATF overnight to dissolve any remaining minor deposits that wasn't cleared out with flossing. If you can, use ultrasonic cleaner with 100% solution of KrudKutter for 12-hours. Thoroughly rinse with distilled water and dry. Don't get any cleaners on rubber diaphragm of slides. Measure and set float-levels when re-assembling. Set pilot-screws at 2.0-2.5 turns out. All this is perhaps maybe 30-40% of refurb job ducatiman does.
Here's good site for working on carbs:
http://www.vulcangadgets.com/files/keihin_carb.html
