Starting a new thread on my HES issue to hopefully get more people looking at it…..


In another thread, I’ve been seeking help chasing down a no-spark situation on cylinders 1-4.  The bike was running on just 2-3.  One suggestion was that I test the HES.  I used Crazy Frogs guide, but not sure I'm doing it right.  And, and in fact I’ve caused things to get worse by what I have done.  I can’t get started at all (i.e., I can no longer run on just 2-3)

Here’s what I did.  First I removed the HES plate from the bike. Just left it hanging, didn’t take the whole sensor off the bike.  I also did not mess with the cup or plate behind the sensor plate. Then I hooked up everything on the HES plug exactly as shown in CF's guide. I'm using the famous radio shack LED light 276-270 (which has the built-in 680 ohm resistor). Got no light on testing pins 2 or 5. I read on the motobrick forum that CF's guide has + and - backwards. I was skeptical given his amazing breadth of knowledge, but thought I should give it a try.  So I switched them, putting + to pin 4 and - to pin 3. Tested 2 and 5, still no light on either. 

On a lark, I put the - running from the LED on pin 3, the + from the battery on pin 4 and then touched pins 2 and 5 with the - from the battery. That gave me a lighted LED on both pins. But when I put a feeler in the HES gap the light stayed on, for both pins. 

I'm confused. I would have thought that, if my HES was bad, since I have no spark on cylinders 1-4, I would have found that one of the two sensors was bad and the other good. But in all configurations I seem to be seeing both sensors are bad (or maybe they are both good?). Or am I misreading things?

Obviously, I’m very confused.  Could someone please set me straight, including any tips on the proper testing method? 



After all of the above, I put the HES back in and I can't even start the bike to run on cylinders 2-3, which I could before. Presumably this means my HES is totally shot, or I killed it during testing, or I reinstalled it wrong. I did mark the position with a sharpie marker before removing it. So that should be correct. However, it would be easy to be off by a little bit. If that were the case, is that likely to cause a non-starting condition?  I was thinking that if it was close, it would run, but maybe poorly.

Very frustrated with myself and would really appreciate some advice.  Thanks!

In the process of testing them you reversed the polarity I recall reading. Regardless of who's right or wrong in the testing proceedure you have fried the HES. I would recommend getting new sensors and puting them on the old plate and not buying a used plate as you could well be buying problems and if you buy new sensors and replace them yourself it's way cheaper. They should be available for around $15-$20 for 2 and if you buy 10 the price goes down heaps.
Have a search around there have been quite a few who have documented the process.

[Insert multiple swear words]! That was exactly my fear.  Don't like the answer, but appreciate the information.  Thank you!  Will do as you say. 

I don't want to revive the recent HES thread and controversy (and I doubt you do either), but could you please tell me who is correct on +/- on pins 3 and 4?  I'd like to know just so I don't ever make the mistake again, and maybe save others from it as well.

As Rick says: http://www.hallsensors.de/Hall-Vane.htm. CYHME56 or CYHME56C.

I cant help you further as I have never delved into the hall sensors, never had problems in that area.
We do need to get it sorted as to what actually is correct.
What I would recommend is that because of the way the sensors are attached to the plate, a permanent fix as in it needs to have rivited parts ground away but the new units are bolted on, get a couple of spares and make them so they can be changed in easily  and if you do have problems down the track it's an easy fix.
I got 6 units a while ago and intend to do all my bikes before anything goes wrong, now that's asking for trouble.

Dai I notice that that mob also have gear tooth sensors so there may be a replacement for the speedo and ABS speed sensors.

My experience with HES is limited so please correct me if I get this wrong. I've not had any issues with HES also, but it seems to be a common enough problem that I've looked into how they work, why they fail, how to diagnose the problem and how to fix.

With regard to the polarity issue, I think we agree that its appears a little confusing. That comes partly from the fact that the diagram on the troubleshooting page includes no wiring colours and information elsewhere on the interweb apears different???
However, I think its reasonably simple to work out the correct connections with the help of the K100 wiring schematics and a visual inspection of the plug from under the tank. I think the important thing to remember is that the colour of the wires off the HES are not important and that's why the wire colours are not indicated on the troubleshooting diagram. What is important, to confirm the correct connections, is the wiring on the harness side of the HES socket.

This is the back of the HES female socket on the harness side (from an old harness I have). The wiring schematic indicates that the top two wires are the power, pos and neg. The outer bottm two are the signal wires. From what I can gather the brown is the bottom sensor and the orange is the top sensor. However, that's not critical. What is critical is to get the power connection the corect way round or you fry the sensors. The large black wire at the bottom is the shielding.


This plug below is the connection to the HES and goes into the front of the female socket above, so as they are photographed, the connections are in the same orientation. So now when you connect your test aparatus to the sensor side of the connector (the male plug), its easy to work out.
You can't see the wiring on this connector because its sealed and also the wiring below may have changed anyway if there has been a previous repair. I've indicated the wire colours from the harness side for simplicity.
The bottom line is that as far as I can work out, the troubleshooting instructions are correct.

I've seen instructions on the motobrick forum which have the power connections the other way round.

I'd suggest that anyone with limited experience, proceed with caution and get advice. Don't take anything at face value. do your research and ask questions if you're unsure. While the sensors are not all that expensive, from what I can see they're a real PITA to change. I think Rick's idea of preparing a timing plate prior to any problems would be the only way you could recover from the side of the road.

*Pinout image deleted due to incorrect info.

Great information Kaptain!  I finally understand the connections.  Somehow, this post should become the default for connecting the HES for testing. 

I think anyone who rides a brick far from home or uses it on a daily basis would be well served to find a working HES assembly and carry it with them at all times.   If you have one with you, it shouldn't take more than an hour to change it at the side of the road.

Of course, we all know that as long as we have a working spare and the wrench and screwdriver to install it, the one on the bike will NEVER FAIL.  The only thing more immortal than a part for which you have a spare is a government agency.

Agreed. This really clears it up. Thank you!

Now to order my sensors and fix the problem......

.......... eh, would anyone like to take time to enlighten an idiot as to what, where and why a Hall Effect Sensor is? (please feel free to snort into your coffee)

riddle the sphinx wrote:.......... eh, would anyone like to take time to enlighten an idiot as to what, where and why a Hall Effect Sensor is? (please feel free to snort into your coffee)

Beginners answer, I also had the problem.

Am open to correction on this.

Effectively the Hall Effect Sensor is a crankshaft position sensor. Most modern engines have one in some shape or form. Cars often have it or something similar [abbreviated to a CPS] and sometimes put in horrifically inaccessible places. It gives a signal relative to the rotation of the crankshaft when the engine is running.

The electronics need this signal to know what the engine is doing. If its detected as running you get fuel being pumped, you get spark at the right time. If the signal is faulty or non existent or disrupted in any way these things don't happen [other input signals are also provided elsewhere but ignore these for now]. You get no engine running.

Olde worlde engines had points and ignition timing, typically on a plate on the end of the crankshaft. The K75/K100 HES detects the exact timing of the engine. The plate is adjustable to a small degree but that's for a different discussion.

Age and where they are sited affects them. These Ks came into service 33 years ago and some are still on original units. With any older bike some things might fail and some things WILL fail. The HES is generally regarded as a WILL fail.


The easy bit.....its behind the T plate at the front of the engine. Accessible with a hex key.

The frustrating bit for some, unless you own a naked K.....the other end of the connection [as in the plug connector] is buried under the petrol tank for safe keeping.....So, off comes the tank which means off come the fairing storage boxes which mean off come the metal frames underneath the storage boxes so you can get the tank off. Then you have to get at the cable route which means off comes the right hand lower fairing panel and the duct from the radiator cowl panel to the air box. And off with the front radiator cover panel. This lot sounds frustrating but if you look after your own K this with practice and having the right tools can be stripped off in less than 10 minutes. If you have your tank fuel lines sorted and recently replaced then getting tank off is easy. If not expect this to go wrong and have some spare fuel line and replace them, they crack and split if you are trying to remove old ones.

With that out of the way access is excellent. Getting the HES cable in is a case of follow the old route carefully. I had mine swapped in a half hour from start to finish and the bike fired up after. Its recommended to check electronically after changing it but I have been lazy and simply checked the spark plugs for colour.

The T cover has a gasket which is dirt cheap. Its also easily damaged. So I bought a bunch of them and just leave them in the parts box. I also got me a spare HES. Changing a HES can be done roadside without too much bother.

My advice is learn about taking the tank and fairing bits off and about what's under the tank. Its a PITA to the uninitiated but if you have practiced it you know that you know how to do it and also that you won't meet surprises. Or, if paying someone to do it you know they won't be meeting surprises at your expense.

A surprising amount of stuff on the K is extremely accessible and without use of too many tools, right up to starter and alternator. I wrapped the tools I used at any time to work on the K, including vise grips, pliers, various allen keys, sockets, spanners, plug wrench, wheel bolt socket, hacksaw blade, screwdrivers etc etc and the whole lot weighs in well about 2.5 kg and with a little more thought got it down to under 2kg. Easy to lose this on an RT/LT or in the ducktail.

thank you Olaf,

To run, an engine needs three things, an explosive mix of fuel and air, a means of containing the explosion, and some heat to get it to explode.

Back in the real old days the heat came from a spark that was triggered by breaking an electrical circuit.  That break was caused by opening a switch by a bump on a shaft connected to the engine.  These were called the points.  they had a nasty habit of wearing out and burning. 

Around the 1970's some government guys said that unless we all wanted to ride bicycles like the communists in China(which is what they really wanted) the automobiles needed to get lots of miles while making the air coming out the exhaust cleaner than the air going in the carburetor.

And the cars had to do it for 100,000 miles without needing a tuneup.  Well, the government guys thought that they had killed the automobile, but the guys who built them decided they liked making cars and so they worked real hard to find ways to do the crazy things the government guys demanded.

One of the main things they needed to do was get rid of those nasty old points that had to be adjusted or replaced every 3 months.  Somebody noticed that a guy at one of the transistor companies had a buddy who was a space alien from Roswell, New Mexico and he showed them how to make a transistor that only let electricity go through if there wasn't any magnetic stuff around. 

One of the car guys got the idea to use that transistor to replace those nasty points.  Since the magnet didn't have to touch the transistor, but could just fly by it there was nothing to wear out.  Since nothing wore out, it worked forever and never needed adjustment.  The government guys weren't happy, but they couldn't do anything.

They called the transistor a hall effect after the guy who got the idea from the alien(they couldn't spell the alien's name).  The alien didn't care, 'cause he had gone on to tell other guys about other cool stuff like Velcro and PacMan.

Anyway, the Hall Effect thingy replaced the points and everything was cool.  The guys at BMW when they heard about the Hall Effect thingy from the transistor sales guy decided to use it on the new K motorcycles to make the spark plugs spark at the right time.

To make it work, they put a little t-shaped enclosure on the front of the engine just above the water pump, and in a hole under the cover the put this little cup shaped thing that had a couple holes in it on the end of the crankshaft.  Then they put a couple of the Hall Effect thingies on a plate so that the cup would spin past the thingies interrupting their magnetic field and making the spark plugs spark at the right time.

These Hall thingies were so cool they could do other things besides make the spark go at the right time.  They could tell the other electronic stuff that the engine was turning and could even tell how fast it was turning.  And nobody even had to even know they were there.

The only problem was that the alien came from a planet very far from the sun and since it was real cold there all the time(they didn't have SUV's to cause global warming) the people on his planet never noticed that the Hall thingies could get f-d up when they got too hot.  As we all know, K bikes get pretty hot.  Most of the time they don't get hot enough to mess anything up, but sometimes the heat that is there along with the engine vibrations can make the Hall thingies stop working. 

Usually, they get better when they cool off, only to stop working the next time they get hot again.  when they get to that point, they can make getting around on your K bike a real pain in the butt, so you need to replace them.  BMW knows how important they are and as a result they hold them hostage at the dealers for massive amounts of ransom money.

Fortunately, they can be found on ebay being sold by guys who take old bikes apart.  If you want new, there are places where you can buy the Hall thingies that BMW uses without the fancy BMW mounting plate.  Instead of hundreds of dollars you only have to spend 30-40 bucks.  The only downside is that you have to take off the old ones and replace them with the new ones.

every day's a school day.

That's why I love this forum.

An excellent post .75!

I reckon that same alien guy is the reason why my new tv is only about 35mm thick and my old one was about 3 1/2 feet.

Always glad to have the opportunity to make technology accessible.

riddle the sphinx wrote:I reckon that same alien guy is the reason why my new tv is only about 35mm thick and my old one was about 3 1/2 feet.

That's easy. Its either 3.5cm or 3.5 feet. Numbers are the same.

It's a bit like us having the same weather as the guys down under. 35 degrees either way. Just a minor difference of Fn things or Cooking thingies.

I think that darn alien read the numbers but had trouble with the dmemominemodemonations.

On a more serious note I hope you make it over this way some time. Even better if you like camping. Our midges aren't as big as the Scottish ones.

Thanks Justin.

If one sensor was still functional and the test result failed, the only 2 things that comes to my mind is that the LED polarity was reversed or it was a factory defective LED.
This would not burn the sensor or the LED, but in this case the LED would never "light up".

If you still have the LED, could you plug it on a 12v source (battery) to confirm that it's working?

I feel very sorry for your troubles, but as you can see you are learning a lot. Kudos on you for contributing to the general knowledge of others.


Cheers,

CF

The LED definitely works. That was my first thought and a concern. I ruled out at the time of the testing. I'm pretty sure I had my polarity correct on the LED, but am not certain on the point.

I should have kept notes and been more methodical. It is possible that I did it wrong the first time and fried them immediately. I'm starting to second guess myself now.

But one thing is certain: I hooked up the 12v both ways to the HES and therefore they are both fried.

Glad to do my part to increase everyone's knowledge. Hopefully next time I can do it without frying expensive electrics!

just an after note
I have been using some leds recently (rated for 12 volts ...with the dropping resistor inbuilt )....PLUS  an additional diode in the anode leg .....so no current flows if they are reversed ....and they don't seem to blow up .

so ....if you looking to do this ...perhaps these might be a good option to lookout for ?
()

I find it a point of embarrassment that I've been all over the works but not yet been over to seem my neighbours, one day for sure. so as for the midges? I can leave the twelve bore at hame aye?

OP wrote:As I said in the OP: "I read on the motobrick forum that CF's guide has + and - backwards. I was skeptical given his amazing breadth of knowledge, but thought I should give it a try."

Oh dear, people really need to get out of habit of wiring stuff up backwards, " just to see".

You could usually get away with this way back when there was nothing more than bulbs and a battery. But there is lots of stuff where polarity DOES matter these days. Most semiconductors ( ie just about anything called "electronic" ) just won't take it even for a microsecond.


I have a mate with a flat twin who insists on connecting everything backwards and mixing wire colours up and burning stuff out. Having fixed it all for him a couple of weeks ago and seen it working, he called me up the next day with the same problem ( and some new ones ). He looked a bit miffed when I didn't spend another day with him redoing what I already fixed once.

Please pay attention to this stuff, it's a lot more sensitive to abuse that it used to be.




Could you quote and link where you read Crazy Frog's guide was wrong?  


It isn't wrong and I don't think anyone said it was. It was cited as being a lot more thorough and probably correct.

They agreed the pdf on their site was wrong but left it there. :cyclops: 

Maybe you could check back and see whether or not you misread what was there about which version was said to be incorrect.

riddle the sphinx wrote:I find it a point of embarrassment that I've been all over the works but not yet been over to seem my neighbours, one day for sure. so as for the midges? I can leave the twelve bore at hame aye?

Hoots mon nay need for the 12 bore, sure we got our own here.

Personally I like chemical warfare as its less annoying to the neighbours- Citronella candles perform a treat and never travel without hem

As for me, with a name like Maxwell sure you know where that comes from.....

Born Again Eccentric has become a regular visitor, most recently only a few weeks ago.

As for not having visited, having spent time sailing up and down the Western Isles sure in good weather you would never want to leave. Awesome scenery and places to visit. But, we do have nice places here too. And lots of roads that the K just loves.

92KK 84WW Olaf wrote:And lots of roads that the K just loves.

Not sure mine does after January. It still has signs of the rash it caught.

A little corn starch in its undies will sort that rash out mate

I wanted to report that I installed a new set of Hall Effects Sensors tonight and it cured my problem!!!!  Thank you to all who helped with this and my other thread when I suspected a coil problem (that may or may not have been the case...one tested weak, so if that wasn't part of the problem, it would have been in short order).

Also, in reply to Beamer's comment above, I'm pretty sure that I misread the info on Motobrick. I went back to look at it and it actually is quite clear (at least given my knowledge now).  In addition, I think I may have viewed the information before some clarifying edits were made about 2 weeks ago.  I think it was less clear in the past, but probably it was sufficiently clear that I really should not have misread it.

Anyway, I'm thrilled to be up and running again.  Best regards, Justin.

A question for you, Justin.  When you got in under the cover and examined the HES, did you find you also had to replace the wiring to them?  I raise this question because I've read elsewhere that the wiring insulation fails due to the hot environment.  It may be that this is an issue on the BMW oilhead engines, which I'm told run hotter than our old K-bikes.  What's your take on this?

Good question, Brickrider. I've heard the same thing. I was concerned about that so I replaced the plate, sensors and wires with this:
http://www.euromotoelectrics.com/mobile/Product.aspx?ProductCode=BOIgnSen-K033EDL

The wire on mine looked OK, but not great. I didn't cut into the wire to see if there was a failure anywhere inside since I'm quite sure that I messed up the testing procedure and fried the actual sensors (actually, my belief now is that I had one bad sensor and fried the other one by reversing the polarity during testing).

My bike was a 1985K100RT with 87k miles before I converted it to a cafe racer. With full fairing in the summer it was intolerably hot to ride. Hard to believe anything could be hotter... I can't say definitively whether heat was a factor in my failure or not. The wire on the new sensor is very rubbery and supple.

List Price: $598.55

Our Price: $219.00

Sale Price: $175.00

You save $423.55!

Wow quite bargain ! If they can slash their prices like that we can see the kind of margins they are running when charging 600 bucks.

Since the sensors cost less than $20 a piece they still aren't doing to badly.

Yes, your original description is consistent with one failing sensor. That seems very likely.

EME are now the only suppliers of Moto Guzzi alternator upgrades (280w -> 370w). Guess what - the price went right through the roof when that happened. A good 70% increase on what I paid for mine when you could shop around.

Dai, that's a bummer. Yeah, the price was a bit high--though I didn't find anyone else offering a non-OEM replacement for the whole unit. And used ones were going for $100. I figured for $75 extra I could be sure I wouldn't have a problem. They were very prompt and helpful in responding to questions. And they shipped to me by 2 day post, even though I only paid for regular shipping. And the part seems to be of good quality. So I, overall, I'm pretty happy. OTO I would not be happy if I had to pay 70% more.

I bought the sensors some time back when there was the group buy.  However, since my '85 K100RS is running well, I've yet to install them.  I'm not sure what material I should use if it seems wise to replace the wires back to the main loom.  Is there a special grade of wire for that environment or is any automotive wire likely to work well?  Would using a heavier gauge be wise?

I can't offer an opinion on wire type or gauge....I'm not knowledgeable in this area. I can tell you that the gauge of the wire on the aftermarket unit I got was close to if not identical to the OEM unit. Seems to me that since all that's traveling on these wires is a small blip from an electromagnet not much is needed on wire gauge. But someone more knowledgeable should weigh in.

brickrider2 wrote:I bought the sensors some time back when there was the group buy.  However, since my '85 K100RS is running well, I've yet to install them.  I'm not sure what material I should use if it seems wise to replace the wires back to the main loom.  Is there a special grade of wire for that environment or is any automotive wire likely to work well?  Would using a heavier gauge be wise?

the thing that could make a difference is the plastic - rubber  insulation

there are several grades which resist heat

your typical pvc insulation is good for maybe 60 - 80 deg c

so ....look for something rated for at least 110 c , as we know that the bike is pretty constantly near 90c to 100 c as It approaches anything mounted on the engine

the copper inside the cable wont have issues ...but its the insulation that matters

perhaps someone could do a little homework on this

I have found some multicore Teflon insulated cable about the right size and conductor count  here

http://au.rs-online.com/web/p/multicore-industrial-cable/2509137022/

they say its good for up to 150 c

made by belden  and expensive for us lot out here

I guess that bmw have fitted what was available back in 83 - 84  ,,,but there are alternatives that are now available

just to add something to this discussion

This looks like the insulation Enduralast use on their HES harness (from EME). Its rated at 500°F/260°C continuous exposure.
http://www.ebay.com/itm/Red-insulation-fire-sleeve-hose-insulation-protection-1-4X3ft-6MM-4AN-/161995589256?hash=item25b7b08688:g:TYAAAOSwDuJW1~bG&vxp=mtr

Splicing the new sensors into the existing harness close to the timing plate to retain as much of the original shielded harness as possible is explained in this article. See P.11
BMW Oilhead Hall Effect Ignition Impulse Sending Unit (1,354 KB .pdf)

yes Kaptain that outer sheath would help but I still recon the Teflon out of the outer insulation and direct to the hes soldered connections would certainly see out our riding lives done and dusted ...the little bits before the shielding starts is the critical bit I'm thinking .  ?

Agree charlie