Need some more details. Are you checking the clutch with the engine running and warm or is it just sitting cold?
Was the clutch properly disengaging before you stored the kart 4 months ago? If so, the cable is probably is set correctly, but it’s easy to check it. Pull the clutch lever and look at the inside of the motor (near seat) to see if it’s moving the clutch engagement lever.
The clutch will always have some bite even when completely disengaged and it’s even more bite when cold (the clutch fluid is very thick when cold). Also, the clutch plates will occasionally stick together when they’ve been sitting still for a long time. You can usually just put it in gear, pull in the clutch and rock the kart back and forth until they break free. It will probably help to start the motor and warm it up for a few minutes.
Hope that helps, but let me know if not and we’ll try a few more things.