There are no specs I am aware of. I recall about 1 mm.
With the 3 small Allen screws loose, there is a little play which allows you to center the star wheel by eye.

I have never used a puller because it's too akward.

The star wheel can be tight on the shaft.
I use penetrating oil (Not WD-40) for a few hours.
Then, clamp the distributor securely between pieces of wood in a vice.
Place 2 big flat screwdrivers across from each under the THICK part of the star wheel and resting on the walls of the housing.
Now, take a deep breath and push down hard on the screwdrivers with sudden force.
It's the leverage that does the trick.
The fulcrum-point is the housing wall with the shorter leg towards the star wheel and the much longer leg towards the handles. That multiplies the force applied under the star wheel.
As it moves up on the shaft, watch for the very small dowel.
Penetrating oil, big screwdrivers and leverage. :)

The distributor has to come appart. Otherwise, you cannot clean and oil the very important advance mechanism, especially the center-bearing. It has to be completely smooth.
Try again and let us know if the above worked for you.

Thanks greatly Gunter, I'm going back in....;)

Mike...:cool:

This is something I would advise everyone to do. It is so easy took me about 1 hour. Now my dizzy was not exactly what I would have called dirty the spindle moved freely though felt a bit gummy. I opened it up as per Gunters instructions cleaned oiled re-assembled and installed. Must say I noticed a difference immediately. Re-set my igniton timing to 25deg BTDC @ 4,000 rpm. The car is running a lot better, now roll on Thusday to get her to the Bosch man to get my CIS tweaked....

Vacuum advance connection
 

I am a little confused - which vacuum connection is correct for the distributor advance?

'78 SC

I have a vacuum line coming from the front of the TB (front of car) and another coming from the rear of the TB (rear of car). I thought the front line was vacuum advance for the distributor and rear line was for a device in the air injection system. (which I have removed and need to plug)
Somebody please set me straight!

For a '78, you should have vac advance only, no retard.
Is the Bosch number on your distributor 0 237 306 001 ?

Vac advance goes in the rear of the TB (front of car)
Where exactly did the vac line from the front of the TB go to?
Which devise?
Picture would help.
There is no air injection system in an SC. Ooops, '78 has the pump.

Distributor vacuum line
 

My distributor number is 0237 306 001 PGFU 6.
So I am correct - the vacuum line coming from the front of the TB (front of the car)
is the one that needs to connect to the distributor.
I will plug the other one that went to a device for the air injection system.
Pictures attached if it helps the story.
1st. photo - '78 dizy
2nd. photo - vac line to dizy
3rd. photo - vac line to air inj. device
4th. photo - device that receives second vac line
http://forums.pelicanparts.com/uploa...1243568520.jpg
http://forums.pelicanparts.com/uploa...1243568715.jpg
http://forums.pelicanparts.com/uploa...1243568741.jpg
http://forums.pelicanparts.com/uploa...1243568772.jpg

Photos reversed - sorry!

Ah so, the '78 still has the air pump for emission control. A lot of people take that pump and the lines out and plug the holes in the cylinders.
But you may not be able to do that if you have AirCare inspections?

If you remove the retard line from the TB, the emission control isn't going to work.

You have the right distributor.

could someone please clarify how you are reading off your advance numbers ? I read to mark off a white paint mark every 5 or 6 mm ? wich is it 5 or 6 ? because it makes a difference once you get around a bit . also does each paint mark represent 1 degreee or 5 or 6 degrees? Also do you start at z1 ? and go which way around the puley ? I have a timing light and am ready to go

Thanks in advance , the rest of the thread is excellent and once i get these questions nailed down I am going to try it

Thanks all

On an SC 1 mm is 1 degree. I do not know if this is true for other types.
So the only thing you need to take care off is from where you start measuring the total advance from Z1 or 5 BTDC. I would only put one mark, that for total advance.

Look at the specs of your car to find the total advance permissible at high rpm as this is the only thing that matters when setting advance. When you idle the advance will then drop wherever it needs to fall. I was mistaken a long time that it is idle advance you should look at but that is indeed not the case.
I believe an SC is 23 degrees at 6000 but scroll this post to be sure or better look at the specs.
I never got my full advance but that is due to a tired dizzy.

Good luck.

Michel

5 or 6 mm is the question? Taking Michel's calculations a bit farther, for a 127mm diameter pulley, 1 degree of advance is 1.1 mm on the rim of the pulley. So 5-6 degrees is 5.5-6.6 mm.

How wide is your paintbrush? Are you making the paint mark with the pulley on the car or on the bench?

As Michel points out, the total advance at 6000 is the key. 5-6 degrees is only the rough starting point.

Oh, and the measurements are taken from Z1, to the right as you look down on the pulley as installed.

One slim white paint mark 5 mm to the right of Z1 and another at ~30 mm is good enough. The 30 mm mark would be about your max advance @ 6k RPM if the distributor advance works correctly.
Max advance might already be @ 5000 RPM.
Disconnect and plug the vacuum lines.
Paint the marks, leave the distributor loose/snug, have someone rev to 5k RPM, carefully turn the distributor to the max mark, stop the engine, tighten the distributor. Re-start and re-check the settings.

What year is your SC?
Stock?

Gunter and others,

Great thread, I am deep into it on my 80 SC dizzy. One thing I can't figure is how to detach the vacum advance?

I assume the end inside the dist is what comes out, but I can't seem to get it loose, or see insdie well enough tell what's going on. Is there anything more detailed than "slight upward movement and wiggling the inside connector arm down at the same time"?

Thanks for any tips

Kinsley

I got the vacum advance out. It was so filled with junk that it was sticking.

Absoulutely incredible how much crud was in there and how easy the advances move after cleaning an lubing.

great thread. how different is this procedure for a 1976 2.7 CIS distributor with points?

Somewhat similar. Inspect closely and use common sense to dismantle.
Only remove it when the pulley is on Z1 with #1 cylinder on compression stroke.

I serviced a few point-distributors but didn't post a write-up. Going by memory, the vacuum attaches differently to the advance plate. Don't lose the small ball when disassembling.
After cleaning the weights/springs etc. , lube the parts including the upper part of the shaft: Put a few drops of oil under the small felt plug but don't open the screw under the felt. Move the upper portion of the shaft and observe how the spring-loaded weights interact. A few drops of oil under the felt should be done as regular maintenance but is generally overlooked.

The shaft shouldn't have any radial play.

Set the clearance for the points and use a tiny bit of grease on the tab that contacts the hex on the shaft when running; lube keeps the correct gap longer.

I think the '76 has vac retard instead of advance??

yes, it has retard. i checked it by unplugging the hose from the tb and sure enough the idle went up. i sucked on the hose and idle went down. not by much but it did go down.
i will take the dizzy apart now and check those weights.

ok, got it apart. not a big deal at all.
the stouter of the 2 springs seems to have stretched. it does not hold tension whatsoever. take a look at the pic. i imagine there must be some sort of seat or something for the spring on the tab where it sits, but there is not one. the weights moved pretty freely although i did notice at first that they did not go all the way out. after i moved them all the way out to the stops then they moved more freely.
so what should i do about the spring?http://forums.pelicanparts.com/uploa...1262540901.jpg

The seat for the spring is usually a small plastic bushing on both sides. I don't see any in the picture. Looks like nothing is holding the spring.

Bosch does not supply parts. Some shops that do rebuilds make their own parts.
You cannot leave it like that.

Your choice: Find a used distributor in better shape for your year, or find a shop that rebuilds distributors.

This distributor hasn't seen any TLC for many years, lots of rust and looks like the tiny parts just rotted away?

Does the shaft have radial play?

i seriously doubt this dizzy has ever had any tlc.
there is not really any play in it. if i keep moving it around i get a slight tick but that's partly due to the vertical play. if it has play it is probably not even measurable.
could i make my own seats? i have some thin black tubing that i use for the smoke systems on my rc planes. it is chemical and heat resistance. it has about .17" od and .08" id.