Triumph Repair: distributor, vacuum distributor, spitfire 1500

Question
i have a 1980 spitfire 1500 with su 4 carbs the distributors vacuum does not seem to be working should i change it to mechical the car does run under power but start fine

Answer
Brian, I don't understand what you are saying. "The distributor's vacuum does not seem to be working" It either works or it doesn't work. What do you mean it "Seems not to work"?

"Should you change it to mechanical?" A vacuum distributor has a mechanical advance in it too. Do you mean change it to a mechanical "only" distributor? Why do you want to do that? Why not just fix the vacuum unit or supply what ever is wrong?
Howard