well friends I have a liana too have done 10,000 km. I bought the petrol version and got it converted after 1500 kms. There is nothing wrong with it and the milage with AC within city is 85 to 95 km with 55 cylinder and on long it is 165 to 175 km with ac. I have 195 tyres. I dont see any missing in it and have to get the rpm fixed after like 15 days but now I can fix it my self :).
Yes the liana with factory fitted cng cannot be adjusted. It is degined in a way that it adjuts it self. It does not require tapet adjustment as well they also adjust them selves.
I have heard that ff cng lianas have a lot of problems but not sure. I am very Thanful to Allah that my car didnt even had a minor fault except for few loose connections which ae a must in all pakistani assembled cars :).
Dont worry take your car to the dealership stand on their tails if they dont listen visit suzuki office and put your foot on the tail of their engineer they will fix it for sure.
trust me this car is better than any other car in 1300 cc
have fun while driving.