Hi everyone.

This is part 2 of the neverending saga which sees me despearately trying every trick in the book to get my 1984 K100 back on the road.
If I leave the bike for a few days, I am able to start the engine but it quickly dies. I have checked the wiring, all current/voltage readings appear to be correct, but today I noticed a discrepancy with a few of the voltage readings!!!!!!
using a multimeter, i measured the voltage at Pin 15 of the Ignition coils and the readings for BOTH ignition coils was approximately 20.6 volts? i also measured the voltage at the fuel injectors (connectors) and the reading was approximately 24 volts! i double and triple checked the measuremernts!
My understanding is that the voltage readings should be approx 12 volts?
Can anyone please explain what is causing this problem, and is it posssible that this situation is preventing my bike from starting?
i am thinking perhaps it's a faulty alternator or voltage regulator?
any help is appreciated.


Regards
Gabriel (1984 K100)

Hi Gabriel,
What voltage are you reading across the battery at about 3,000 rpm?
Also are you sure your meter does not have the times 2 button stuck down. There used to be a well known brand of analogue meter that had a times two button which doubled the reading.
Regards,
K-BIKE

i can't measure the voltage across the battery at 3000 rpm because the engine wont start! I used a digital multimeter and I can assure you that the readings are correct. I have been advised by an auto electrician that this situation is caused by a faulty alternator/voltage regulator, but I am interested in other people's opinions about this sitruation.

I never seen this kind of problem.

Disconnect your alternator and check the voltage again. (you may have to recharge your battery first).

If everything check OK, try to start the bike without the alternator plugged in.

Hi,
In your first post you said the engine starts but it quickly dies. Are you measuring the 20 or 24 volts when the engine is briefly running or when it has died?
Regards,
K-BIKE

One of the computers (EFI or ignition) may have a security shutting itself down if the voltage is too high.

i measured the voltage across the battery terminals and I got 25 volts. somethings tells me this is very wrong. I assumed the correct voltage is 12.

25 volts at the battery?
Is that a 24 volts battery?
Just unplug the battery and plug you car battery to try it.

I retested and obtained the correct results. I was using the multimeter incorrectly. I feel very foolish for making such a simple mistake, but would like to say thank you to all who responded to this thread.

OK, everybody makes mistakes. What is your plan B?
Have you checked the page on the EFI troubleshooting?
If you get electrical power where it's supposed to be, I would suggest to replace the fuel filter and check the fuel pressure.
The pressure may build up when the pump is running, but as soon as the injectors release the pressure, the system may not get enough flow to keep it constant at 36 PSI.
This would be a simple an inexpensive item to check or replace.
Keep us up to date.

Bert