Intermittent. Any ideas ?

[tvrla]

Most of the original system has been replaced, and doesn't leave much - just the ignition switch and kill switch.

Depending on how frequently this happens - once every five minutes? - once every ten miles? - you might try running a hot wire to the coil and going for a ride. See if the fault still happens.

[Luca]

Before pulling it apart you can bypass the switch to see if it's the culprit.

If you still have intermittent problems, it's either the wiring to the switch or something else.

[georgesgiralt]

Hello !
Last week things were becoming worse. So I decided myself to wire the voltmeter to the ignition coil to monitor the supply voltage and see if it drops when the phenomenon arose....
Two days ago, I came back from work, (early 'cos I started before dawn at work) and decided to check that strange idle I had and wire the voltmeter to the coil.
So I started to look at the plug, found one sooty black and decided to tune the mixture as the bike was hot. 30 seconds later, the bike stopped. No more ignition. Nada, zilch.
The bean can Hall sensor had decided to die from a heart attack and go to the paradise of the sensors... 31 years old. Was kind enough to bring me home.
I feel lucky.
And to ease the things a bit, a friend of mine provided me with 4 bean cans, and a new sensor. He had a deal : I fix mine using my spare sensor bought month ago, fix one of his and return to him whatever part I did not use.
He told me there was a bean can still functioning well when cold. So I can still ride to work with the BMW.
Life is so good at times !
I just have to open 4 boxes and fix 2 or 3 of them ( I may have a Siemens sensor coming )...
So if you experience ignition shut off for a second or two, could be the Hall sensor asking for retirement... Keep that in mind ...
And thanks for the advices and help !

[georgesgiralt]

Hello !
Just a follow up on this :
I've replaced the failed sensor on my bean can by a Siemens HKZ101. And on one spare bean can, I replaced the failed sensor by a Honeywell 2AV54 which is now unobtainium....
If you've to buy a new sensor, buy Siemens !
The rivet on the 2AV54 are solid metal which is very hard to pry so you'll have to hit it hard if you want it to stick on the plate. At the risk of deforming the plate or killing the sensor if unlucky... Unless you've a hand press and tooling available...
On the other hand, the Siemens rivets are tubular type. So using a conical instrument you pry them open, then finish the job using a steel bar and a hammer. The metal is quite soft, so it's a piece of cake to affix it to the plate !

[Bob_Roller]

Could you see any physical damage to the sensor, like coming apart

[georgesgiralt]

Alas not.
I think it could be some sort of poisoning due to the goo used to seal the electronics inside the sensor's box.
Ages ago, I worked in a factory producing sealed electronics and they had a forensic department to analyse such failures. I wish I could ask them (I would be younger and they won't be gone bankrupt... )
They showed me a box from which a very big capacitor had literally disappeared being eaten by the "fumes" from the goo. On X ray, the cavity was still showing but when they dissolved the goo, surprise !

[Bob_Roller]

I checked the availability of the Siemens Hall sensor in North America, doesn't appear to be a commonly available part here .

[nhmaf]

I *just* ordered some of the Chinese replacements for the Honeywell 2AV54 part.   The Chinese part # is CYHME56.   They also specify a replacement part for the oilhead sensor Siemens HKZ101, and that chinese part #CYHME301.   Both parts appear to be electrically the same, but there are some subtle differences in the mechanical drawings.   They may ultimately be interchangeable in the airhead beancans anyway, but I thought that I would get some of their "officially" specified replacement part for the Honeywell to test.   I have a bean can which I presently don't know if it work or not, so I'll test it and if it needs repairing I'll try one of these Chen Yang Technologies replacements out on it.

[georgesgiralt]

If the Chinese replacement for the Siemens part is mechanical identical, you'd better choose this one as the riveting job would be a lot easier...
It seems that Siemens either sold it's sensor division to someone else or stopped producing it because the Siemens sensor I got is flagged obsolete on some components sites I checked. Mine fits perfectly into the bean can and the "look" is perfectly identical (mounting wise) to the Honeywell.

[Bob_Roller]

Ther've probably sold the manufacturering rights to another company, that's what Honeywell did with the 2AV54, they sold the rights to  a Chinese company, there wasn't enough demand for the part ot make it worth they're while to continue manufacturering them .

[Bob_W]

Last time I checked, Newark had the Honeywell for less than $12.00. Only one problem, minimum order 1,000 units. I was a little short of cash that week and put off the order for another day.
Seriously, this tells me, Honeywell will run a batch for a large enough order.
Anyone had good or bad experience with the Chinese units? My understanding from having read "how to" threads elsewhere is the sensors are not the problem, but instead wiring attaching the sensor to the plug deteriorates with heat and age. These things are getting older after all. Some repair threads talk about using special high temp wire and heat shrink. I would think, and that's a good way for me to get in trouble, the wires used for eyes on an electric range should be able to handle the heat.
No personal experience.
Bob

[georgesgiralt]

Actually, one bean can I am trying to repair had a wire broken between the 3 prong plug and the bean can. Physically nothing was apparent. I discovered this after having replaced the "failed sensor", destroying it, soldered the new one on the hold harness and testing it. As it was not working, I thought, at first, I had destroyed the unit. But upon further inspection, testing the sensor directly, I discovered that one wire was dead... I had to patch the wiring outside the can (as the male Junior timer plug is unobtainium, AFAIK)...  So if one of you has a source fr the AMP junior timer 3 contacts male plug, speak now  

[Bob_Roller]

Hi Georges, saw this on a site that I'm ordering a headlight wiring harness for my '87 Guzzi .

Saw a section for connectors, probably not cost effective for a few low cost parts, but this may give you an idea of what's available for connectors for the 'bean can' .

http://www.easternbeaver.com/Main/Elec__Products/Connectors/connectors.html

[georgesgiralt]

Yes Bob, I've seen this site before.
If I've to replace the AMP junior Timer connector, I'll go the waterproof AMP 3 way connector one can find at the nearest auto part store (as they use plenty of them into modern cars ).
The nearest shop is 5 minutes from work and stock them in blister pockets, so you've just to pick them and pay ;-)
If, on the other hand need more wires to fit into the connector, the story changes. And you may be forced to order from the other side of the planet....
I'm fortunate enough to have saved the male connector.
I'm really wondering if the sensor was really faulty on this bean can ! We never know now...

[Bob_Roller]

You can construct a tester for the sensor, just requires a 9 VDC battery and an LED .

http://robfrankham.co.uk/bike/vane_switch_tester_circuit.htm