I decided to completely dissasembly and re oil the dizzy (and de-oil so its dry inside after, too much oil not good). See photo
I am glad I did because I found a problem by accident that would , if not noticed, have made the whole advance/vacuum redundant.
on dismantleing and removing the vaccum from the main dizzy it came straight off leaving the arm (and spring) pointing out the side of the dizzy. Thjs I found out later should not of happened.
There is an arm (and spring) that connects the serated wheel to the diaphram inside the vacuum.
This arm has a screw thread on the end that goes into the vacuum and this obviously must be screwed into the diaphram inside. See photo
This enables the the vacuum to pull the diaphram then the rod then alter the dwell on the serated wheel. (makes it go in and out)
Mine was not screwed in. Therefore meaning the whole diaphram would not pull the arm and therfore not adjust the advance.
I would never have known what was wrong had i not opened it all up.
To replace, I know now, that the arm and spring must be attached to the vaccuum bell and then re-attach it to the main dizzy unit and then the serated wheel.
I hope this helps someone who is stuck.
