1 Starting problems on a 87 K100 Wed Jan 06, 2021 7:00 pm
Ccanov
active member
Hello!
I recently bought a 87 K100 (produced in 08/86) which did not start. The previous owner left the motorcycle in the garage for three years, but he said that was working fine before that… who knows. I decide to try, the price was good and always want to do something like this, so..... why not give it a try?
After a few days checking, reading, and trying to make myself familiar with all the components, I decide that was time to start with the funny part.. I keep reading all kind of trouble shooting posts to get different ideas (i did not try the transmission oil on the throttle body yet..) but I am going to keep looking for info, just adding my own post so you can hear the bike and maybe help.
Now… I have been following the Bertrand Vogel (Crazy frog) troubleshooting guide during the past weeks trying to figure out what was going on.
The starting point: motorcycle cranking but not start to keep idle. The lights are on, when I click the starter light off so looks good. In the video I keep the starter button depressed.
What I have done:
- Pin 13 (ground), I have 0.3 - 0.4 ohms but not 0.
- Pin 10 (water temp) I have 3.3k ohms (I guess that its cold the water or is there something else I should check here)
After all this measurements and replacements, I remembered that the owner told me that he move the airflow meter Allen screw (5mm), and also the throttle body screw (the one in the middle to adjust idle), so I am not sure what is the default position for the screws, or is trial and error...
I went with the trial and error (for the air meter) and starts for one time for 25 seconds at idle, and that’s it, no more starts So… should I close it and open 2 turns?
I am not sure how this motorcycle usually sound, I record a video for the 20 seconds with the sound, to be honest I did not expect to get it started, haha probably you guys can tell something else from the sound and smoke (taking into consideration that was not started for 3 years)
Any help is welcome.
Thank you so much.
I recently bought a 87 K100 (produced in 08/86) which did not start. The previous owner left the motorcycle in the garage for three years, but he said that was working fine before that… who knows. I decide to try, the price was good and always want to do something like this, so..... why not give it a try?
After a few days checking, reading, and trying to make myself familiar with all the components, I decide that was time to start with the funny part.. I keep reading all kind of trouble shooting posts to get different ideas (i did not try the transmission oil on the throttle body yet..) but I am going to keep looking for info, just adding my own post so you can hear the bike and maybe help.
Now… I have been following the Bertrand Vogel (Crazy frog) troubleshooting guide during the past weeks trying to figure out what was going on.
The starting point: motorcycle cranking but not start to keep idle. The lights are on, when I click the starter light off so looks good. In the video I keep the starter button depressed.
What I have done:
- Replace fuel pump, fuel filter, fuel pressure regulator and external fuel lines (PO had these parts new, so I prefer to start with the new parts to remove them from the equation)
- Replace crank breather (kind of z hose from the block? to the airbox?)
- Replace the rubber between the throttle body and the black box.
- Check tank conector, ICU and EFI connector. All cleaned with a contact cleaner.
- Fuse box (all ok) / Relay (I hear clicks in there , my bet 90% they are working fine, but I should learn to test them)
- Clean the grounds (frame, gearbox, and coils)
- Idle switch (I hear the click when I turn the throttle, so I leave it like that)
- Fuel Injectors, I removed the injectors and clean them with the carb cleaner spray and a kind o tool on amazon that comes with the connector to the battery, and a kind of plastic to put in there the injector. More than clean, I just want to double check that I have some kind of spray from then and were not broken... I have the spray when I activate the contact.
- Air flow meter: test the resistance with the temp variation at home, and also the different pin combinations (at the air flow meter contacts, not the connector). The value changes if I move the vane. Pin 7-5: 102, Pin 7-8: 357, Pin 8-5: 358, Pin 8-9: 208)
- Coils: for both coils I get the same values: 2.3 primary, 9.9k on the other, secondary?
- Compression test: 165psi.
- Measure valves clearance: all within spec.
- Hall sensor, I had a new one, so I mount it just to discard that piece too. I was scary testing this part, because looks like its easy to break, so I mount the new one.
- EFI Connector:
- Pin 13 (ground), I have 0.3 - 0.4 ohms but not 0.
- Pin 10 (water temp) I have 3.3k ohms (I guess that its cold the water or is there something else I should check here)
- New plugs NGK D7EA (from any reason PO has Iridium NKG something...). Plugs or ignition wires are plugged properly, and I also check for spark with a “spark tester”.
- So far, and to keep it simple, i did not mount back the airfilter box, so if i need to access some places its easier. I have the AFM connected but without the box, i guess i do not need it to make it work, but just so you all have the same info. I will mount it as soon as the motorcycle works and after a good clean. Unless you guys told me that I need to improve the airflow or something like that. I assume is just for the filter, but i may be wrong.
After all this measurements and replacements, I remembered that the owner told me that he move the airflow meter Allen screw (5mm), and also the throttle body screw (the one in the middle to adjust idle), so I am not sure what is the default position for the screws, or is trial and error...
I went with the trial and error (for the air meter) and starts for one time for 25 seconds at idle, and that’s it, no more starts So… should I close it and open 2 turns?
I am not sure how this motorcycle usually sound, I record a video for the 20 seconds with the sound, to be honest I did not expect to get it started, haha probably you guys can tell something else from the sound and smoke (taking into consideration that was not started for 3 years)
Any help is welcome.
Thank you so much.
Last edited by Ccanov on Wed Jan 13, 2021 10:16 pm; edited 3 times in total (Reason for editing : Updating with more testing (compression, valve clearance) sme parts replaced.)
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BMW K100 (K589)