It didn't start out to be a bad day. A quick, 40 minute, lane splitting ride to SF's VA hospital for a echocardiagram and then down south to visit Greg's "R Bike" shop. Then a quick shot across the San Mateo bridge and up the much maligned I-880 to home. I was doing ... well 70-80 mph in the express (motorcycle) lane when it all went.. dead. Well the motor just stopped and I coasted across 4 or 6 lanes of high speed traffic to fetch up against the sound wall. I couldn't believe how noisy that road is without my earplugs in. Thirty minutes of checking fuses, computer connectors and every thing else I could think of. Bike turned over real well but wouldn't start. Panicky calls to my brother, nephew and Greg, got a lot of advice but no one was in a position to come and help. Did I mention that 8 to 10 bikes had shot past and no one even glanced in my direction. I was weighing my options of walking out, the nearest exit was 1/2 mile, when lo and behold a AAA tow truck swings in front of me and asks if I needed help. Oh, yeah. Expensive no doubt but could he do it? Well, no. But he did offer to put me in touch with a friend who might be able to. And after a bit of phoning around he said they would come and get me but the price was USD $225. for the 10 mile trip. Yeah! Sure will do! He exchanged information with the friend and left. Shortly thereafter another motorcycle capable tow truck pulled up in front of me. I greet the driver but he's not the guy who was summoned but another. How Much? USD $100. flat rate, his response. Oh YEAH! man lets toss it up there. We're rolling it up when tow truck three shows. Driver is a gentleman and doesn't make a fuss about who was there first. Not sure of the legal ramifications but I've not signed anything. So Driver #2 gets me home, I pay him $100 and tip him $20 just because. Seriously doubt that this business went on the books. Anyway now to trouble shoot. Electrics appear to be working but when preparing to get the tank off I check the return fuel line. Nothing, Nada. Oh a culprit. Some serious time spent checking reveals that I've got an open line across the power lines to the fuel pump. I open the tank and pull it. A double check shows it's not working. Checking through my parts bin I find two, a 52 mm one and a 43 mm one. See the photos below. Replace the bad one with the 52mm pump and after the usual time spent replacing, checking etc. I try it out and the bike starts right up. 

But why did the fuel pump fail? I've never really looked into one and so having a bad one and ordered a brand new replacement. (Decided to not trust 2nd hand been sitting around for years backup) I open up the bad one looking into it. The first photo is a comparison of the 52 mm vs 43 mm pumps. You can use either but your filter and the vibration damping rubber are different. The plastic mount however is the same. Things I learned. But a K100 plastic mount differs from the K75. The second photo shows the damping rubber and plastic mount (forgive the wires coming from the left). The third photo is of the internal parts. It's basically an electric motor. The fourth photo shows the two brushes but if you look close there is an electric wire in the upper right which has broken from its solder joint. This is the culprit. My best guess is that the soldering may not have been the best and that vibration caused the wire to work harden and then break. Otherwise the pump is in good shape.

Thanks for the detailed explanation with pictures of the pumps.
All information like this is worthwhile to tuck away in our memory.

As an experiment I've been running a $34.00 Aliexpress copy pump since July 2017. I did have my OEM pump in the tail as a backup which has since been  replaced with another Aliexpress pump. The pump has been exposed to some hard running in extreme temperature conditions and hasn't missed a beat.   Link http://www.motobrick.com/index.php?topic=10054.msg86054#msg86054
Regards Martin.

MartinW wrote:As an experiment I've been running a $34.00 Aliexpress copy pump since July 2017. I did have my OEM pump in the tail as a backup which has since been  replaced with another Aliexpress pump. The pump has been exposed to some hard running in extreme temperature conditions and hasn't missed a beat.   Link http://www.motobrick.com/index.php?topic=10054.msg86054#msg86054
Regards Martin.

I just knew this would be the result just as soon as I placed the order. Well EME is a bit cheaper than BMW
https://www.euromotoelectrics.com/category-s/3232.htm
But very reputable. Do you have a link to the Aliexpress unit?

This is the link to the one I got. https://www.aliexpress.com/item/32828842178.html?h 
This is the links to a couple of Pabokay ones   https://www.aliexpress.com/item/32826407380.html? & https://www.aliexpress.com/item/4000701070039.html? If you type in BMW K100 or K75 fuel pump in Aliexpress it will give you alternatives but you'll have to wade through all the incorrect ones.
Regards Martin.

Thanks for the tale and the fault finding pictures and diagnosis. Great help. 

Gave me flash backs to my fuel pump induced breakdown last October! Sounds like you were better served by the breakdown folk than I was…a cynic could think that perhaps an ad hoc call out for cash is more lucrative business than responding to a pre-paid customer!

https://www.k100-forum.com/t17469-fuel-pump-woes#201560

My fault lay somewhere within the through tank connector (Part of the fuel sender unit on my K100 LTs). In the safe sanctuary of my garage, having proved beyond all reasonable doubt that the plug and pump were good and that the wiring had continuity to and from the through tank connector but not through it…I did some destructive examination of the moulded polythene (or some such) through tank connector. All that achieved was the destruction of the connector…it’s not designed to come apart! The only indication of a possible internal problem was a slight discolouration.

Having had some issue with the fuel pump in my 83 K100RS....have it coming on 4years and the previous owner had told me the fuel pump was not seated right. There were other issues too, like tank only eventually good for 70 miles. That turned out to be blocked filter basket.

Anyway having bought lots of spare bits from tills.de I bit the bullet and changed everything our of the tank, hoses, filter, pump, mount, damper. It all worked out at a few cent over €100 for the entire. 

The mount was the issue, the new one I got was not the same as the one that came out. New one fitted and all looks good now..

The old pump etc was still working but it dated from 98 and the hoses were original.

Born Again Eccentric wrote:
Gave me flash backs to my fuel pump induced breakdown last October! Sounds like you were better served by the breakdown folk than I was…a cynic could think that perhaps an ad hoc call out for cash is more lucrative business than responding to a pre-paid customer!

I had a number of thoughts on the subject of tow trucks and operators. Wondered if the AAA driver was to get a kickback from the tow truck driver he called. Wouldn't be surprised. In fact the fellow that I went with tried to give the operator of the 3rd truck a bit of cash. That operator refused it and actually gave us a hand getting the bike up on the tow truck tilt bed. So in some senses I was quite lucky despite the ill luck of having the pump fail. Had a few minutes to talk with the driver who took me home. Young fellow. Not over 25 would have been my guess. Due to my own current situation with medical plans I asked if the business owners provided him with health insurance. No! Typical American system. He was on his own as far as medical or anything else went. I didn't ask about what his financial relationship to the company was. My best guess is he is relatively new to the game as he didn't try to gouge me as much as the AAA driver's friends did. He did ask me how much they were going to charge me. Apparently he got the feeling that he had under priced them quite a bit. I lied and said they hadn't told me yet. Well $100 is a bit less than $225. But I also got the feeling that he was returning from a previous job and I was extra money in his pocket. So tacking on an extra $20 as a tip felt right.  But you are definitely at their mercy. I could have walked out of the freeway, gone and rented a truck, driven back to the bike hoping no one had looted it, loaded it, taken it home, unloaded it and returned the truck. But $120. was very cheap in comparison even $225 was acceptable compared to all the time and effort to do it myself. Very seriously being stranded by the side of a major freeway, with all the noise (I could barely make out what folks were saying on my phone) and the heat 80+F standing there in my Aerostitch for over an hour was an extremely stressful situation.

You need to get an AAA RV Gold card.  It's about $90 a year and makes you eligible for free towing up to 200 miles, travel planning, hotel discounts and some money for living expenses while your bike is repaired when you're away from home.  Lots of peace of mind when you're touring a couple thousand miles from home.  If you are riding in a group, your card will cover towing for the people riding with you.  It also covers all your other vehicles.

Triple A is the best road service because they pay well and quickly to the tow drivers.  Everybody wants to work for them, and nobody wants to get bad reviews at the AAA, because then they lose their contract and it's almost impossible to get it back.

Point-Seven-five wrote:You need to get an AAA RV Gold card.  It's about $90 a year and makes you eligible for free towing up to 200 miles, travel planning, hotel discounts and some money for living expenses while your bike is repaired when you're away from home.  Lots of peace of mind when you're touring a couple thousand miles from home.  If you are riding in a group, your card will cover towing for the people riding with you.  It also covers all your other vehicles.

From what you say I assume you are saying they cover motorcycles. I didn't think that was true in the past when I had AAA.

Are there other insurances which will cover a m/c? I checked my "Progressive" policy aka "Ride" insurance and they don't mention it as a benefit.

You have to have RV Gold.  It covers anything on the road with a license plate.  My progressive policy has towing, but I don't use it because insurance companies are slow pay to the tow company.  They will put you to the bottom of the list if it's a busy day.  AAA tows get there a lot faster because they don't want any complaints to AAA and they know they'll get paid at the end of the month if not sooner.  Go to the AAA office and talk to them.

Point-Seven-five wrote:You need to get an AAA RV Gold card.  It's about $90 a year and makes you eligible for free towing up to 200 miles, travel planning, hotel discounts and some money for living expenses while your bike is repaired when you're away from home.  Lots of peace of mind when you're touring a couple thousand miles from home.  If you are riding in a group, your card will cover towing for the people riding with you.  It also covers all your other vehicles.

Triple A is the best road service because they pay well and quickly to the tow drivers.  Everybody wants to work for them, and nobody wants to get bad reviews at the AAA, because then they lose their contract and it's almost impossible to get it back.

Well, thank you .75; you got me to thinking and investigating why I didn't already have roadside insurance. I just paid for this coming year on 4/7 and so switching companies doesn't make sense. But I did check in with Progressive. Seems I have been transferred around a few times between local insurance agencies and in the process no one bothered to inquire if I was interested in road side service. But a call to Progressive/Drive got it added for and additional $21./year and roadside assistance with trip interruption was $5. more or $26. So I went ahead and added the roadside assistance. AAA may be the premium service but I can afford $26. Of course that's only towed for 15 miles. Would be curious what charges would be for a longer distance.

But thanks for getting me thinking.

best regards
J.

jjefferies wrote:Very seriously being stranded by the side of a major freeway, with all the noise (I could barely make out what folks were saying on my phone) and the heat 80+F standing there in my Aerostitch for over an hour was an extremely stressful situation.

‘I couldn’t really hear much at all due to the noise of the passing traffic (I have an app on my phone that measures noise - it recorded a steady 85dBA i.e. the noise level normally associated with using power tools)’


The only way I could hear my phone calls with the breakdown services was to put my crash helmet back on and use the Bluetooth on my phone to connect with the speakers/microphone in my helmet.

I had 4.5 hours of standing, sitting, lying at the roadside (major freeway = UK motorway). Incidentally, in the UK, the “Control of Noise at Work regulations 2005” mandates that at or above 85 dBA, employers must provide hearing protection and enforce its use. Above 87 dBA, they must prevent exposure…Perhaps explains why I now often see people doing highway repairs with ear defenders on.


When I was doing long commutes to/from work, I started to detect hearing impairment (backed up by evidence in audiometry examinations during my annual health check). From that point onward, I have always worn earplugs when riding. I previously assumed it was the noise from my bike (albeit muffled to a degree by the crash helmet) but my roadside evidence suggests that the drone of the other traffic is a substantial contribution

Born Again Eccentric wrote:
When I was doing long commutes to/from work, I started to detect hearing impairment (backed up by evidence in audiometry examinations during my annual health check). From that point onward, I have always worn earplugs when riding. I previously assumed it was the noise from my bike (albeit muffled to a degree by the crash helmet) but my roadside evidence suggests that the drone of the other traffic is a substantial contribution

I Hear you Bro (small joke ) Likewise tinnitus has claimed me though I don't like wearing hearing aids. And without them I find I can fill in some of the most boring conversations with wit and amusement. You wouldn't believe some of the things I've overheard. People keep asking why I'm laughing in some conversations. If they only knew what I'm hearing them say. But likewise I always wear ear plugs. For anyone not already aware, tinnitus is the ringing in your ears that obscures other sounds and in particular the frequencies of human conversations. I'm told that in one study they inserted tiny microphones in subjects' ear canals and could actually hear the tinnitus. Apparently it's in part traumatized cilia, the little hairs that pick up sounds in the inner ear, continuing to whip around. Traumatized after years of being subjected to repeated loud noises.

I don't know how it is in the UK but in this part of the states (Calif) they have forgone previous attempts to ameliorate Freeway noise by planting trees in favor of the cheap approach of building sound walls on either side of the Freeway. This is particularly true in urban areas. But it doesn't work very well as all it does is cause the noise to echo around and eventually escape. My home is several miles from the nearest Freeway and day or night I can hear the Freeway noise. I was once at a BMW (auto) shop and a older woman (we now refer to them as Karens) came up and accused me as representing all bikers as causing all the noise on the Freeway. It was amusing as all I could hear were autos.

komandoalicante wrote:En estos casos recomiendo si hablamos de una K75 o una K100 de 2V un  pequeño trocito de cable.


Quitas el fusible #6 y el conector de la izquierda haces un puente con  el positivo de la bateria, en ese momento la bomba se tiene que poner en marca, asi sabemos muy rapidamente si tengo un problema con la bomba.


En el caso de ser una 16V yo tengo un antiguo conector de una vieja instalacion electrica con la que le puedo dar corriente a la bomba de forma muy rapida, desccartando el problema,


Tambien he tenido un problema con los conectores electricos de ese elemento que hacian mal contacto dandome muchos problemas fantasmas, busque los conectores completos y no los encontre, pero tube la enorme suerte de encontrar los pines (machos y hembras de esos conectores) y una vez cambiados desaparecieron todos los problemas y el reloj de la gasolina dejo de volverse loco, la empresa se llama berner.

Sorry using computer translations but

Efectivamente, entiendo que en tu situación no pudieras hacer nada hasta llegar a casa, pero por experiencia ante una moto muerta lo primero que suelo mirar es eso, pues si estoy de viaje llevo siempre una bomba y si no ya se directamente que tengo que llamar a la grúa.

Era mas como informacion adicional que como respuesta a tu tema

In Northern California, AAA has a Premier level of membership for about $75/year. It covers two 200 mile tows per year. Over the years they have towed my K100RT but they have also towed an old CBX which was a basket case and the brakes were rusted so three of us pushed the bike (skidding) onto the truck and he dropped it off at my house (for a full restoration). My son used the tow service when he bought a new bike and wanted it delivered to his house (60 miles). Last year I had AAA tow a Yamaha I had purchased to restore - and it didn’t even have an engine. So what’s the downside? Getting a tow vehicle capable of handling motorcycles can take as little as two hours and as long as six hours (plan accordingly).

Definitely true that AAA is the premier for towing. But for $26. to get towing, albeit at a much shorter range, and trip interruption. How much is your AAA membership charge? Just wondering as someone told me you have to have a premier membership.

Just call or go to the AAA office and ask about RV Plus.  They will give you the current straight scoop on it.  Different regions will have slight differences in what they cover and how much they charge.

Then talk to a AAA tow truck driver.  Ask them how fast they respond to a Progressive call vs. a AAA call.  Unless Progressive has stepped up their game a lot recently I am pretty sure what the answer will be.  I'm speaking from experience, I had the Progressive coverage and ditched it for the AAA.  More peace of mind at 9:30 at night 2000 miles from home.

About 7 years ago, I was out in Durango, Colorado with a group of people from all over the U.S.  At 10 o'clock in the morning one of the riders who was from California had the voltage regulator on their Honda VFR shit the bed.  They called Progressive and were told a truck would be there the next morning.  We were on the side of the road at least 10 miles from the nearest town.  One of the other riders had AAA RV Plus and called the AAA.  We had a truck there in under an hour and they took the bike to the Honda dealer in Durango who said they couldn't have parts for a week.  The truck then took the bike to the U-Haul where they rented a truck to take the bike back to California.

While it costs more, the AAA covers all your vehicles, in some regions they cover boats, snowmobiles, utility trailers and bicycles too.