My 1985 K100 has a problem where it will run for 10 minutes and then dies.

I had replaced my Hall sensors themselves by drilling out and riveting new ones in the old wiring harness and plate but that didn't fix the problem, so I just bought a new Hall Effect Sensor for Euro Moto Electrics. However, now the bike won't start at all. For troubleshooting I put my old one back in and it still behaves as before - runs 10 mins and dies.

Could it be that the sensor I bought is faulty? I lined the new one up with where the old plate was, is it possible the timing is off and it needs to be rotated to work?

Anyone have a guess?

(I've replaced or tested swapping in from another bike the ECU, ICU, coils and radiator temperature sensor so if my problem ISN't the Hall sensor I'm just at a loss)

This image is of the original Hall sensor reinstalled, and the new one I tried held up in front of it

timz10000 wrote:Could it be that the sensor I bought is faulty? I lined the new one up with where the old plate was, is it possible the timing is off and it needs to be rotated to work?

Could you post some clear photos of your installation?

Laitch wrote:

timz10000 wrote:Could it be that the sensor I bought is faulty? I lined the new one up with where the old plate was, is it possible the timing is off and it needs to be rotated to work?

Could you post some clear photos of your installation?

Just updated the post to include image

With the cutaway on each place lined up at the worst it can only be 180° out and that will make it backfire etc.
Are you getting any action at the injectors because the 4 injectors all four fire from the 2-3 pulse and if that is missing (no pun intended) then no fuel is injected.
Check for spark and fuel injected but not at the same time as your auto club probably wont do a rescue from orbit.

is the alternator actually charging the bike battery whilst running ?

or is it just going flat (at the edge of going flat at least )

k bikes like a good strong battery , and with no other information  could this be an issue ?

Since I've basically swapped out all components that would be obvious culprits of this problem I'm wondering - is it possible that the wiring under the tank could cause this problem? Would it be worth my replacing that? (Or the fuses?) I have a parts bike so I can try swapping things if there are good components to try (but I've already ruled out ICU and ECU).

I also haven't dug into the ignition switch, that worth doing?

Today when I ran it (with my old Hall sensor) it wasn't firing on all cylinders in case that helps troubleshoot (black smoke and sounded a little rough)

To recap: the bike runs for 10 or 20 minutes then cuts out and won't start until cool again.

charlie99 wrote:is the alternator actually charging the bike battery whilst running ?

or is it just going flat (at the edge of going flat at least )

k bikes like a good strong battery , and with no other information  could this be an issue ?

The alternator does charge the battery and my battery is pretty new

timz10000 wrote:Could it be that the sensor I bought is faulty?

From your description, it sounds like the new HES from Euro Motoelectrics is faulty. It might be an idea to bench test it.

There will be five connections on the HES connector:
Red: +ve from battery
Black: -ve from battery
Orange: Signal from HES #1
Brown: Signal from HES #2
braid: shield from cable

On the bench, you'll want a 12V power source like a battery, a 12V LED bulb with pigtail wires, the HES sensor and a feeler gauge. The LED bulb is polarized and will only light if the anode is connected to the +ve and cathode connected to the -ve. Test this to identify the anode and cathode (usually the cathode is the outside base of the bulb).

Procedure:
1. connect +ve from the battery to Red on the HES connector, -ve from the battery to Black on the HES connector
2. connect the anode of the LED bulb to the +ve of the battery,
3. connect the cathode of the LED bulb to Orange
4. the LED should be ON. Pass the feeler gauge blade through the sensor #1 and the LED should extinguish
5. repeat 3. and 4. for the other sensor

It will be obvious if either of these tests fails. If so, the HES is defective.

timz10000 wrote:I also haven't dug into the ignition switch, that worth doing?

Today when I ran it (with my old Hall sensor) it wasn't firing on all cylinders in case that helps troubleshoot (black smoke and sounded a little rough)

To recap: the bike runs for 10 or 20 minutes then cuts out and won't start until cool again.

From this updated description, it still sounds like the HES sensor is defective.  Since you are using the old one, it's understandable that you haven't proven the problem to move with the part, namely one would expect that replacing the HES should eliminate the symptoms if the HES is to blame.

You stated in the first post that the individual sensors were replaced in an existing plate.  That means, I'd expect both sensors to be good, but the symptoms you describe above are indicating that one of them is bad.  I would perform the same validation test I described above on the installed HES to make sure that both sensors are working.  I'd do this before investigating the ignition switch or going to the hassle of replacing the wiring loom.

robmack wrote:

timz10000 wrote:Could it be that the sensor I bought is faulty?

From your description, it sounds like the new HES from Euro Motoelectrics is faulty.  It might be an idea to bench test it.

There will be five connections on the HES connector:
Red:  +ve from battery
Black: -ve from battery
Orange: Signal from HES #1
Brown: Signal from HES #2
braid: shield from cable

On the bench, you'll want a 12V power source like a battery, a 12V LED bulb with pigtail wires, the HES sensor and a feeler gauge.  The LED bulb is polarized and will only light if the anode is connected to the +ve and cathode connected to the -ve.  Test this to identify the anode and cathode (usually the cathode is the outside base of the bulb).

Procedure:
1. connect +ve from the battery to Red on the HES connector, -ve from the battery to Black on the HES connector
2. connect the anode of the LED bulb to the +ve of the battery,
3. connect the cathode of the LED bulb to Orange
4. the LED should be ON.  Pass the feeler gauge blade through the sensor #1 and the LED should extinguish
5. repeat 3. and 4. for the other sensor

It will be obvious if either of these tests fails.  If so, the HES is defective.

Thanks - I'll try this today on both. I'll post what I find out

Just to be clear, when I say "12V LED bulb", I mean a LED meant to run from 12V. This is not a regular LED. A regular LED can be used but be sure to also solder in a 1K Ohm resistor in series with one of its legs so that the current is limited when used. 12V LED bulbs can be obtained from any automotive aftermarket store to replace normal automotive incandescent bulbs.

robmack wrote:Just to be clear, when I say "12V LED bulb", I mean a LED meant to run from 12V.  This is not a regular LED.  A regular LED can be used but be sure to also solder in a 1K Ohm resistor in series with one of its legs so that the current is limited when used.  12V LED bulbs can be obtained from any automotive aftermarket store to replace normal automotive incandescent bulbs.

Thanks - I think I have a 12V LED tester bulb that came with this motorcycle's extra stuff.

timz10000 wrote:

robmack wrote:

timz10000 wrote:Could it be that the sensor I bought is faulty?

From your description, it sounds like the new HES from Euro Motoelectrics is faulty.  It might be an idea to bench test it.

There will be five connections on the HES connector:
Red:  +ve from battery
Black: -ve from battery
Orange: Signal from HES #1
Brown: Signal from HES #2
braid: shield from cable

On the bench, you'll want a 12V power source like a battery, a 12V LED bulb with pigtail wires, the HES sensor and a feeler gauge.  The LED bulb is polarized and will only light if the anode is connected to the +ve and cathode connected to the -ve.  Test this to identify the anode and cathode (usually the cathode is the outside base of the bulb).

Procedure:
1. connect +ve from the battery to Red on the HES connector, -ve from the battery to Black on the HES connector
2. connect the anode of the LED bulb to the +ve of the battery,
3. connect the cathode of the LED bulb to Orange
4. the LED should be ON.  Pass the feeler gauge blade through the sensor #1 and the LED should extinguish
5. repeat 3. and 4. for the other sensor

It will be obvious if either of these tests fails.  If so, the HES is defective.

Thanks - I'll try this today on both. I'll post what I find out

edit: am trying this again will advise

timz10000 wrote:

timz10000 wrote:

robmack wrote:
From your description, it sounds like the new HES from Euro Motoelectrics is faulty.  It might be an idea to bench test it.

There will be five connections on the HES connector:
Red:  +ve from battery
Black: -ve from battery
Orange: Signal from HES #1
Brown: Signal from HES #2
braid: shield from cable

On the bench, you'll want a 12V power source like a battery, a 12V LED bulb with pigtail wires, the HES sensor and a feeler gauge.  The LED bulb is polarized and will only light if the anode is connected to the +ve and cathode connected to the -ve.  Test this to identify the anode and cathode (usually the cathode is the outside base of the bulb).

Procedure:
1. connect +ve from the battery to Red on the HES connector, -ve from the battery to Black on the HES connector
2. connect the anode of the LED bulb to the +ve of the battery,
3. connect the cathode of the LED bulb to Orange
4. the LED should be ON.  Pass the feeler gauge blade through the sensor #1 and the LED should extinguish
5. repeat 3. and 4. for the other sensor

It will be obvious if either of these tests fails.  If so, the HES is defective.

Thanks - I'll try this today on both. I'll post what I find out

Howdy - Hm.... I tried this on both my old Hall that works (at least for 20 mins until the bike fails) and also the brand new one. I couldn't get the LED to light on either. (The LED does light when I connect in circuit alone with battery).

Any idea what that means, or is perhaps your connection scheme not correct?

Actually I found this diagram http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/efi-web%20page/K100%20troubleshooting%20Starting.pdf which I'll look at later tonight to see if it's the way I did it

My description is based on the following document: http://users.rcn.com/dehager/service/oilhead_hall_sensors.pdf

Double-check the wire colours. I am going off the K100 schematic diagram colouring but it may be possible that the actual wire colours on your sensors could be different.

The following can also help you:
https://www.k100-forum.com/t11004-hall-effect-sensor-testing
http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/electrical/Hall_sensors/Hall_sensors.htm
https://www.k100-forum.com/t5192-homemade-multifunction-ignition-timing-abs-code-reader-injectors-tester

robmack wrote:My description is based on the following document:  http://users.rcn.com/dehager/service/oilhead_hall_sensors.pdf

Double-check the wire colours.  I am going off the K100 schematic diagram colouring but it may be possible that the actual wire colours on your sensors could be different.

The following can also help you:
https://www.k100-forum.com/t11004-hall-effect-sensor-testing
http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/electrical/Hall_sensors/Hall_sensors.htm
https://www.k100-forum.com/t5192-homemade-multifunction-ignition-timing-abs-code-reader-injectors-tester

Thanks for the help everyone! I got a replacement Hall sensor and it seems to have fixed that problem. (Now I have another problem which I'll post separately about)