Thread: Lucas V8 dissy nylon clip repair method.

Originally Posted by mark2

My rotor is stuck fast to the shaft. I think I'd break something if I tried to remove it......

What are the symptoms of the broken nylon clip?

Usually when you pull hard on a stuck rotor button the clip breaks and the mechanical advance falls apart as it lifts up further than the clip should allow it. Then your rotor button becomes free to rotate about 1/4 turn and the cap won't go back on again. And it won't run.

You will need 3 screwdrivers. One inserted next to the rotor button to hold down the internals. Two to rock the rotor button sideways and off. You may need assistance if you run out of hands. The nylon clip breaks easily if you exert too much pull without holding the internals down.

The dissy I featured in the pics below was like this which is why it was the guinea pig. I broke the rotor button getting it off. I am guessing your dissy advance hasn't been oiled for years so it may be seized too. A drop of oil under the button every 10 000km. Clean the end of the dissy shaft carefully and find a new rotor button if needed.

In his book ‘XJS experience’ , KP outlines a solution for the same problem in Jag V12 dizzies.

He suggests a couple of thin brass washers held in by a 9/32x 5/32x 1/16 o-ring. The o-ring fits the groove on the top of the rotor shaft and the washers retain the carrier