[I]if any of your friend or any one else you know own the same make model of car without any modifications check for - Speed & RPM in the panel - Khyber comes with a size 12 wheels from factory Till 1990 it was known as Suzuki SWIFT SA 310.
what is sitaution when engine is idling - do u see any hicups, some intermittent unstable vibration ? means some Iginition current issue. check distributor cap for any fractures, plug wires for cracks ( best test is in dark ) if there is any current leakage the blue arc will be visible in darkness when car is idling. change if necessary.
also check of there is noticable delay in pickup when shifted to 2nd and pickup further delay when shifted to 3rd asking for more throttle. - if such is the case most likely clutch is worn out -
come back to forum with the solution when your mechanic resolve the issue [/I]