Boxerworks.com

The VW module that ends with 351 should be a direct replacement according to this http://bmwmotorcycletech.info/ignition.htm
With the Automega unit I bought it wouldn’t start at all, next to test is a Siemens from the 80’s. Hope that works, it’s also the cheapest.

You said: "Checking the timing with a strobe ignition timing light, got the timing perfect a couple days before the ICU blew."

Was the bike running perfectly at that point?
If so, that to me would indicate that the timing chain is OK. It didn't just f**k up overnight. Timing chains on these bike will just get noisier and noisier and noisier with wear; never seen one skip a tooth or break.

I think that your tach shorted out and caused the ECU to blow. If you dare take your tach apart (good luck putting it back together) you will most likely find that corrosion in it is the source of your problem.

These guys can probably repair your tach http://www.paspeedo.com/ but only do that after the bike is up and running well without it.

Yes, it was running without any issues. There wasn’t much left in the adjustment even then, was almost as CCW as it can be.

I’m not that kind of guy who likes to pay people to do things for me, I’d rather learn to do it myself. Lots of time, not so much money
So I’ll try to fix the tacho myself or replace it with something better looking.

I opened up the bean can again, all seems to be in order, thought that maybe the hall effect sensor can rotate but it’s securely locked so no adjustment in that. Might have to grind that cog holding pin a little...

Hmmm, looks like the drive cog installation can affect timing. Now I have to figure out which way around it should be in there...

Wow! I'd really like to help you out but it seems like you are you are jumping ahead of yourself trying to fix too many things at once.
It's hard to know exactly what's going without being there in person but I'll try. I'm THE BEST at sorting these issues in person, usually in just a few minutes, but it's a lot harder to determine exactly what's going on remotely. Patience please.

BEFORE BUYING ANY MORE PARTS...
...THE FIRST THING I WOULD DO IS HOT WIRE YOUR IGNITION. This will by-pass ALL possible ignition switch, kill switch, tachometer, funkanwagnall or wiring harness issues.

To do this, first disconnect your coil to isolate it from the system.

Run a jumper wire from the battery POSITIVE to the GREEN wire on the ECU and from there to the COIL POSITIVE terminal.
Run another jumper wire from the battery NEGATIVE to both BROWN wires on the ECU.


Back off the hold down screws on the beancan just enough that you can rotate it by hand but it won't move on its own..
NOW (You might want to wear long sleeves to do this as to not end up with exhaust header burns all over your forearms) start the bike and try to rev it while simultaneously slowly moving the beancan in small increments through its full range of travel.


Tell me EXACTLY what happens?

YOU SAID: "Hmmm, looks like the drive cog installation can affect timing. Now I have to figure out which way around it should be in there...*

180 degrees out makes no difference, it works the same either way.

It seems like it does, ignition was even more late when I tried it the other way around. The metal plate that triggers the hall effect sensor is not assembled symmetrically when compared to the drive cog pin hole.

I tried your method of hot wiring the ignition. It will only start and run with the ignition adjusted to the most CCW direction. Struggles to rev and will die after it has enough rpm. Don't know how much that is, I don't have a tachometer. With the strobe the timing is very late, OT mark barely visible at the bottom end of the hole. Might be that with the Huco module it would've rev'd better, I tried with the second one.

Returning the ICU's today, receiving the old VW/Audi part maybe tomorrow or day after that. With the original ICU it tries to start, but only for a few seconds after the ignition switched on.

Should be symmetrical, I have one apart in front of me right now.

Question 1: which replacement advance springs did you use?

Question 2: Can you easily move the hall trigger rotor a few (13?) degrees CW by hand and does it spring back when you let go?
You'll have 2 remove the beancan cover and its front shaft support plate to check this.
Sounds like your advance mechanism is jammed on full retard OR your new springs are way too strong.

Well mine is not, and there's a pin locking the metal plate in it's position. So that's stock.

1. I bought the springs from Motobins, part 72620. Worked fine before the ICU blew.

Have to check the number two.