Hi,
I have an M4 engine that has 123-UNI ignition installed. It is now in my Dyane but when I check the ignition timing it seems to not advance by much. It seems to move around by only 3 teeth rather than the 5 suggested in Ken's post from 2013...
http://www.international2cvfriends.com/forum/viewtopic.php?f=5&t=2745&hilit=hetty&start=580

I have found some instructions for the 123-UNI and it seems to have the correct setting under that Allen headed cover.

My queries are:
1. Anyone aware of a reason why the advance may be off?
2. Should I just adjust it so it is 5 teeth when running at high revs and ignore the alignment when at lower revs?
3. Also there seems to be a gap at the top of the 123 unit - seems odd to me - why does this 123 have a flat top when the others appear to be circular - should this be covered with something?

A pic of the 123:


Many thanks for any advice.
Ian

@Ian
I'm not familiar with the M4 engine. Or even 123 for that matter.

Is there a plate behind the points box, assuming it has a detachable one. The later engine has a plate, and this can be distorted when fitted, resulting in the advance weights not moving correctly. It could be they don't advance properly, or it could be they had not returned correctly when the plate was first fitted.

the weights are taken out with a 123 ignition.

very valid point

So, then ... you have set it up incorrectly, or it's faulty ...

See something strange under the 123 what is that? or is this a Visa engine?

Not a Visa engine, it is a M4 though.

This 123UNI came on the engine when I got it. There isn't anything between the 123 and the space where the magnets are. I was wondering if that gap at the top should be covered with something? What's the strange thing you can see?

Yes that gap i mean, via that moisture can get in. Will it need the covering tin (nr.9) that is in that space with a normal ignition.

1. Wrong advance curve
2. Then You have too much advance at low RPM and cranking may get hard because of too early ignition
3. UNI is for all engines. Remember that early engines, 375cc and 425cc has dynamo on crankshaft, that's why it can't be round like 435cc and 602cc engines

Does 123-UNI have an advance curve for M4 -engine? Can't remember, someone might has a manual for that 123..?

Oh, too easy to find the manual...

https://123ignition.com/manuals/123manual_2CV2016.pdf

Curve 3 should be the right one. You have followed the manual, and still tie 123 gives wrong advance? If so, verify all settings, and if the advance is still wrong the 123 can be broken...