Thanks for yourinput, I should have said that i have checked othe leads including engine earth,and run a new one just in case.
Starter has been off and 'serviced'. Relays, plugs plugleads
etc all have been checked .
I used to be a mechanic for over 30 years apart from owning car spares shops and reconning starters, alternators and dynamo's.
That's why it is annoying me, all the obvous bits are testing working ok.
Still no worries its old and now is going in a couple of weeks