Last time I used the mower the drive was a bit intermittent, some times staying on others not driving. Investigated today, outer sheath of clutch cable broken at the lower ferrule and cable badly frayed, causing it to jam in the ferrule.
So unwound the the broken wires and cut them off at slightly differnt lengths and rewound. Covered that section of cable with a single overlapped layer of self amalgamting tape to stop the wire ends catching on the inside of the sheath. Greased that section and it slides in and out easyly. Reassembled and it worked very well.
Some what to my surprise (for a 15 year old mower) a new clutch cable is easy to find, £10.95 delivered via Amazon Market Place. I wonder how long that will sit in it's packet? The repaired cable only has 3 intact strands of the 18 or so that make up the cable. Couldn't get the remains of the sheath out of the ferrule so the sheath is still "broken" and the path means that there is a kink at that point.