Check for insufficient lubrication of clutch pedal bushing.

Lubricate the clutch pedal brushing

Check for interference of clutch pedal return spring.

Remove and reinstall the clutch pedal return spring.

Check for a worn release bearing.

Replace the worn release bearing.

Check for an improperly installed release lever.

Remove and properly reinstall the fork shaft. Very lightly lubricate the fork fingers at the release bearing with wheel bearing grease.