Easy to change a vaccum unit?

[Arthurdaily]

Hi all - well the car runs well now, my project, but when I suck the vacuum pipe there appears to be no movement or anything... though the car runs fine! So, don't know if it IS broken... if it is, how easy is it to change just the vacuum unit and how do I know WHAT vacuum unit to order - ie how do I know WHAT 'sort' of distributor I have?

Thanks!

[chrisryder]

When you suck on the tube to check for movement, i presume you're doing this with the cap off?

You should see the baseplate inside the dizzy (with the points and condenser on) move slightly as you suck the tube.

If you can keep sucking fresh air then it's had it though. you should meet resistance!

Once you've got that far, you may find it easier to swap it with the carb off the engine, as you have to unhook a little spring off the baseplate to remove it, and re-hook it to fit a new one.

As well as the spring, you need to unscrew the 'knurled' adjuster nut off the opposite end of the 'bell' ...urm... end

You may have to ping a little circlip off before you can get the knurled nut off, but sometimes this circlip is missing!

To find what distributor you've got, just by where the 'bell' meets the body of the distributor, on the body itself, you should see a code. most likely to be 25D.

[edit = punctuation]

[Bazzalucas]

It just so happens I had to do this recently (in situ). With a good needle-nose pliers it was easy.

[Alec]

Hello Chris,

the code is a 5 digit number, 25D etc is the type.
There is also a code on the vacuum unit, three pairs of numbers which tell you the specification, start vacuum, maximum vacuum and advance degrees at maximum vacuum.

Alec

[Arthurdaily]

Thank you!