Franz wrote: NO, no paint on the carbs !!!!
Tell the mechanic to clean both carbs really carefully on both the outside AND the inside with petrol, compressed air and cottonbuds !!
Tasks: check if the floats press on the needle in the right position and close off the petrol flow into the carb bowls. Check the closing needles for wear. Check all jets and clean them with compressed air only. Very important to have the pilot jets cleaned, both for petrol and airflow. Check that the idle mixture srews are clean and set to the right 'turns out'. Should do this according to repair manual settings. Further on if the carbs are flatbed, need to check for wear on the slides, cracks on the diaphragms and that all seals and O-rings are ok. Needles should be set at the right recommended position. Choke valve should be clean and show no wear. Intake scoops from Carbs to cylinder head should be absolutely tight and not allow additional air to be sucked into the engine. Synchronisation is an absolute must. If you don't have any settings, just type the carb make and type into Google and some sites with forums will come up where you are provided with information on how to do. I did that with my Mikuni BST40 on the DR650 recently although mine is now fitted with Supertrapp exhaust, K&N filter and DYNOJET stage 2 kit. Be aware that your jets are not meesed up and original size, need to look at them through magnifying glass. Cheers & happy working, Franz