Hi
I solved problem with the lack of power because of air leakage, now all works ok in high rpm. But I do still have a problem with engine while cold. Works not stable and very bad, like missfire on random cylinders. So I want to adjust hall sensor properly and have strobe lamp but have no idea where to connect (which cylinder) and how to adjust. Also have no idea about angle that should be adjusted. All information welcommed.

Hello man from Krakow!

Maybe this video helps.
https://m.youtube.com/watch?feature=youtu.be&v=p9-i-nBmpVg

Besides a very nice city Krakow, my last trip

There's no need to use a timing light.  Just align the notch in the Hall Effect Sensor with the notch in the motor.

Here's a good write-up that will help you troubleshoot a poorly running K100:

http://www.kforum-tech.com/electrical/EFI/bike-wont-start-EN.htm

Thanks, Man, indeed nice town, never sleeps  

And yes this video helps a lot, just have one concern because there is K75, and the question is if we connect strobe to the third or fourth cylinder in K100??

duck wrote:Here's a good write-up that will help you troubleshoot a poorly running K100:

http://www.kforum-tech.com/electrical/EFI/bike-wont-start-EN.htm

Thanks, that is very helpful for now and for the future maintenance.

"BMW ON" Tech Tips circa Aug 1989

K100 cylinder#1,  K75 cylinder#3

http://forum.kforum-tech.com/members-upload/uploads/Ignition_Timing.pdf

I did like duck said and...all dies. No matter how I did adjust hall later on, motor crank, spark is good but no fire up. I i stuck because it should give a sign of life but no, nothing. So what should I do??? I can not use strobe because engine is not working but now have no ida how to make him work...

PiotrK100 wrote: . . . spark is good but no fire up. I i stuck because it should give a sign of life but no, nothing.

After you've tried starting it, are the spark plugs wet or dry?

Laitch wrote:

PiotrK100 wrote: . . . spark is good but no fire up. I i stuck because it should give a sign of life but no, nothing.

After you've tried starting it, are the spark plugs wet or dry?

Were rather dry, and spark wa very strong.

When you had started it previously, did the engine both run well at high speed and idle well at low speed once it was warmed up?

Laitch wrote:When you had started it previously, did the engine both run well at high speed and idle well at low speed once it was warmed up?

At a high speed did not go well because I found a air leak, so was like power loss. But when cold was running very unstable while idling, warming up gets better but not perfect.

Can you hear the fuel pump run for a second or so after you release the starter button? Are you are certain that the fuel filter isn't clogged, that the internal fuel lines are not clogged and that the fuel lines are tightly clamped and not leaking within the tank? If you are not certain, check them. It is time to use the troubleshooting chart at the link that duck posted in Reply#4.

It's the 4 pin fuel pump connector under tank

Fuel pump is working, pressure on injector lines are fine. But there is too big coincidence that anything else is broken while I touch only hall sensor. I change also spare hall but no change, still crank and no fire up.

PiotrK100 wrote:Fuel pump is working, pressure on injector lines are fine.

There is no sound of ignition when cranking despite what you assert is the presence of spark. The spark plugs are dry despite repeated attempts at starting with what you assert is a functioning fuel system. The hall sensor has been replaced. Determining if the fuel injectors are getting a signal to open might be the next step. The method for that is in the troubleshooting guide of duck's link.

OK, we probably found the reason, which is hard to accept but that is the only way: battery was not fully charged, we crank several times over and over. After fully load engine start up immediately. I know I'm a jerk but what can I say...

PiotrK100 wrote:OK, we probably found the reason, which is hard to accept but that is the only way: battery was not fully charged, ...

It's a tale of steely determination overcoming adversity that will be told around campfires worldwide.

Laitch wrote:

PiotrK100 wrote:OK, we probably found the reason, which is hard to accept but that is the only way: battery was not fully charged, ...

It's a tale of steely determination overcoming adversity that will be told around campfires worldwide.

Thanks Bro.