I can't see any pictures, so something seems to have gone wrong there. Could you try again please?

At the moment it sounds rather more like reel bearing failure or maladjusted reel than clutch failure. When it is exhibiting this "grabbing", if you quickly stop the engine, pull off the spark plug lead, and try to turn the reel by hand, does it spin smoothly and freely? REMEMBER: NEVER PUT YOUR HAND NEAR THE REEL WITH THE ENGINE RUNNING, UNDER ANY CIRCUMSTANCES.