The release levers in the pressure plate and the cover are binding.

Replace the clutch cover.

The clutch release levers are not properly adjusted.

If the levers are in place, adjust the clutch cable.

The clutch release bearing adjustment is improper.

Adjust the clutch cable for proper clearance.

The clutch pedal is binding or sticking

Check the clutch cable for proper operation.

The clutch pressure springs are weak or broken.

Replace the clutch cover.

The clutch facings are burnt.

Replace the driven disc.

The release bearing is binding on the input shaft housing.

Lubricate or replace the release bearing.