When Tidying up (I use the term loosely) in the workshop last night I found the old Bosch electronic/Ignition Control unit for my k100.



Does anybody know of a repair service for these or are they useless once they have failed?

It would be good to have it repaired if possible and keep it for a spare.

88

dont know who does them 88

i still havent looked inside one yet

perhaps someone has an idea ? good luck mate

They usually don't break unless they are the first generation (1984-1985).
They have been replaced under warranty (recall valid for 10 years) because they were not waterproof.
It would be cheaper to find a used one online than paying somebody to fix it.

I've never heard of one failing. What does cause problems is the insulating wrap around the harness connecting the ignition module to the Hall Effect Sensor (HES for brevity). There is a conductive mesh in the insulation surrounding the wires that if disturbed can allow RFI to cause problems with the signal from the HES. It is especialy common at the locations where the harness is zip tied to the right frame down tube (zip tied too tight) and where the wires enter the harness at the ignition module, where it makes a 180 degree bend.

I would test it in your bike before tossing it out. They are not cheap, even used.

I have a spare and a couple of damaged ones, one got wet with some interesting results, the water lodged in the bottom and if you turned the unit sideways it worked!! and another got "spiked" by voltage from the charging circuit of my Briggs engine. I know one that we suspect was damaged by not using a diode protected relay for the injection pump. We have come across damaged shield cable too, as said cable tie damage.
Keep an eye on fleabay and dont pay too much for one, they are not worth much, there seems to be a few about.

Themason wrote: I would test it in your bike before tossing it out.

.

Interesting comments guys, thanks. I was half expecting that it would be uneconomical to repair as CF suggests.

It was diagnosed faulty by a local mechanic who looked over the bike for me when I got it first, it would start but conk out if any throttle was applied. He told me that after trying lots of things he brought the bike to a wreckers yard and swapped out various components until he got it running. The unit that is now in the bike came from that yard at a cost of €60 which seemed reasonable to me at the time. It could be that all the plugging and unplugging he did cleaned some contacts and solved the problem.

I'll definitely test it before passing sentence!

88

Thats not a symptom of a dud ignition unit, more like stuck airflow meter. When the fail they just stop although I have one thats down on one coil only. 60 is not bad but I have bought several for less that 30.

[quote="88KE"]

Themason wrote:The unit that is now in the bike came from that yard at a cost of €60 which seemed reasonable to me at the time.

Price at the dealer is approximately $1,500 . €60 is a fair price as a used one usually sells for an average of $125 or €100.

88KE wrote:

Themason wrote: I would test it in your bike before tossing it out.

.

It was diagnosed faulty by a local mechanic who looked over the bike for me when I got it first, it would start but conk out if any throttle was applied. He told me that after trying lots of things he brought the bike to a wreckers yard and swapped out various components until he got it running. The unit that is now in the bike came from that yard at a cost of €60 which seemed reasonable to me at the time. It could be that all the plugging and unplugging he did cleaned some contacts and solved the problem.

I'll definitely test it before passing sentence!

88

This is the exact problem that Peggy's (me wifey) K75 has. I am fiddling with her (the K75) now. There is hope.
UJ

tio Jaimito wrote:This is the exact problem that Peggy's (me wifey) K75 has. I am fiddling with her (the K75) now. There is hope.
UJ

There is indeed! It seems a recurring theme on the Forum that people who suspected this unit to be at fault ultimately found that the cause on there problems lay elsewhere. Work your way through the fault finding/troubleshooting guides carefully before chucking out the electronics.

88

In my own experience the few times I have had the described symptoms, engine starts and then conks as soon as given any throttle has been tied to two things. I have either neglected to fully seat or fully tighten the clamp on the 90 degree tube from the air flow meter to the plenum, or the bike had old fuel and/or Stabil in the fuel. Old fuel can make them a real devil to start.

by my recconing 88 if you declare it a dud then you can peak inside without fear

I also have one of these units. I had trouble in early 2012 and it was solved when I replace dthis unit. The pointers were to other things but in the end I suspect it may have bene some oft he connections as 88KE says. It was as new inside with no sign of any water entry. O didnt even bother testing it.

There is a guy in Sydney that can fix them and my advice is don't throw them out even if they are cactus.
They may be easy to get now but in another 10 years there may well be a lot of people regreting the big heave ho they gave one.
They dont make them anymore.
How often do we hear things like gee my mate had heaps of them and threw them out (whatever them is).
These Ks are going to be around for a long time and bits will become very difficult to get we should make sure we don't contribute to the items becomming scarse.

If any of you are every down my way I can check them in seconds by plugging them into the craft's loom. I'm not sure how hard it is to swap over in the bike but my "new" wiring box is designed to allow for quick diagnosis of wiring problems.

Send it to me and I will have a look it is right up my alley, only problem is I'm in Aus
Halo

You guys are magnificent, helping hands being extended to other forum members - Good on ya.
Regards,
K-BIKE