KENWOOD x85 Record Speed VR

Hello, i have a Kenwood M85 Separates System from 1991/92, All works great, But i do have a Problem, When i record on to a cassette on the system, it plays back ok on the System, but if i Play the Cassette on any other Stereo the cassette plays slow, thus, the Kenwood is Recording on to the cassette too fast, i have the lid off and on the circuit board there is about 6 Vr Resistors, i haven't touched any or adjusted any, it doesn't say on the board what each one is for so rather than go down the trial and error route i would rather try and find out which one is the correct one to set the correct speed, any help would be awesome, huge thanks in advance.. Paul..