Brother, I am having the same issue with 05 Cultus Carby. I had its engine complete overhaul some 2000 kms ago. Even then mechanic was unable to completely fix the carb. And, all the vacuum hoses were a mess, as he couldnt properly figure out where they go, and had cut off the auto choke.
I had it services, new carb kit, new butterfly etc. but the average is just bad, jerks, unstable RPM, black some with petrol smell.
Can the mechanic you mentioned fix the problem? Can you give his phone number so I can call him up before hands, Thanks a lot.