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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: TrueAce on December 11, 2015, 06:30:08 PM
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Starter Relays appear to be among the TOP topics of discussion......really, just look at all the posts! Does the concept of the most critical link in the starter system "fusing contacts" every time there is lower battery amperage, or a random ground, seem right? Yeah, I know it's a 30 year old bike, but really, is there a more vulnerable electric component in a K75/100 than the starter relay?
After too many failures & replacements ($), I am thinking there is a way to re-engineer the starter system to fuction without an expensive Bosch relay.....hear me out.
So the start switch control input wires connect to the starter relay, connected to battery-in, connected to starter-out. And points get confused & fused. Why not direct wire the battery-starter connection to an appropriately amp single-throw switch, like race vehicles. Ignition "ON", Kill switch "ON", single-throw switch "ON" activates starter........ZOOM. Why does it all have to go throw an expensive, vulnerable, non-solid state/contact fusing Bosch starter relay? Hey?
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Because your mechanical switch remedy has no safety feature to prevent the starter from engaging with the engine running. The starter relay is grounded through the ICU which removes the ground if the engine RPMs are higher than 770.
The best remedy is to find a replacement relay with a lower hold-in voltage than the BMW standard one. That way, a lower battery terminal voltage (due to weak battery) will not allow the starter relay to oscillate around the hold-in voltage.
What happens to cause the starter relay to weld:
If we look at what is happening on our bikes when we push the starter button the starter relay coil effectively receives current via the starter switch and a whole bunch of connections, if the voltage is too low the relay will not pull in because the voltage required to pull in a relay is higher than the voltage required to keep it closed (called its hold in voltage). At that point we push the button and nothing happens, if there is enough voltage to pull in the relay then the following takes place.
With a weak battery there can be just enough voltage to pull the starter relay in, it pulls in and the relay contacts close with a spark at the moment of contact, at that point voltage starts to flow into the starter motor.
The current draw of the starter is huge and as a result the voltage supplied by the battery can sag down below the hold in voltage of the starter relay so the armature of the starter relay starts to release from the coil thereby weakening the spring pressure holding the relay contacts closed until the relay contacts separate and an arc forms momentarily between the relay contacts and then extinguishes. At that point current to the starter motor stops and the battery voltage rises up to the point where the relay pulls in again and the cycle recommences. The high speed pulsing or chattering of the relay and the sparking at the contacts allows them to weld shut at the point when there is sufficient molten relay contact material present when they close and the arc stops. At that precise point as the contact is closed the molten metal freezes and the relay contacts are welded closed and as a result the starter is now permanently running until the battery goes flat.
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Another affirmation that K-bikes are made to be ridden and ridden plenty, or else trickle charged during prolonged static admiration. Thanks for bringing the synopsis here, Robert.
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Thanks, Robert, for your always concise response. I turn to the race toggle solution because a solid starter response is not effected by the input switch, yet when I introduce a lesser amp switch between starter wire and power, no problem starting, and it doesn't run on. Why not eliminate the relay.......what else does it do that a manual appropriate amp switch manually would do?
Ignition ON....check.......Kill switch ON......check.....intermittent starter switch ACTIVATE, bike starts. Can I eliminate the starter relay, and with lights direct wired, the shed relay, too? what am I not understanding, with all the handle bar switches relocated to under seat? Like headlight, i want to direct wire the starter. Guide me guru's, please!
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From my understanding of Robert's post, you can do that which you propose; however, doing so eliminates a feature designed to prevent accidental energizing of the starter and the resulting havoc, unlikely though it seems.
I wonder if I've got that right. I think it's better for me to just keep the battery charged and be mindful of how I operate the switch. A cheaper relay would be nice though, in case I get distracted.
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Laitch, I understand what you're saying. Everything I ride is on a trickle. The K100 is my project bike that I
continue to experiment with. Having successfully removed all the handlebar switches to under-seat, I decided to upgrade that to a lighted array of manual switches......will post photos tomorrow. But the starter relay still bugs me. On a single switch throw (on/-spring back....like on race cars), there will be no continuous run with the starter, or accidental engagement while running. Seems the starter relay, and load shed relay, would be superfluous. I've bench tested with switches, using a beefy starter button, no problem activated the starter. But the damn starter relay just seems unnecessary if you apply race car starter wiring principles.
On top of that K100 story, then I pull the K75 out of the garage after two weeks idle, starts right up, idles for 5 minutes then quits. Start up yields click-click, so after a overnight charge, no click ,no start.....another low battery plus probably fused relay. That's when I began thinking there must be a better way to wire k bike starters than going through an expensive Bosch relay. Surely somewhere in 30 years of K bikes somebody has discovered a better way.
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Well, if there's zero chance of accidental energizing with what you're proposing then I'm not certain I understand Robert's post.
As far as the K75 problem, all I can say is idle bikes are the devil's tools. I think they're especially vulnerable when they're stored for long periods in the comfort of a warm space. When I put mine up for winter, it has always been ridden hard the day before that. It sits in an unheated shop that's far from air-tight although inside is way more comfortable than outside in windchill. The interior temp sometimes goes double digits below 0ºF. The muffler is plugged, the battery removed to be stored and charged once a month off-site in a heated room and that's it. When the temperature is tolerable, I do whatever maintenance is on the schedule until spring. The more I read here, the more I'm thinking it's a miracle that I can just gas it up and go every spring.
I keep reading about the problems arising from corroded, dirty or loose electrical connectors and components. I had one of those loose ones that I fixed in two seconds once I knew where to look. I'm starting to think that riding my bike at a wide range of speed and in wet weather fosters its durability and keeps those miracles coming.
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Yeah, Laitch, I think the battery just reached the end of its service life, but I tried to restart and froze the starter relay,that's my next maintenance task, already have the battery & relay coming. But my K100 project is a non-stock project that I am going to apply my Dale Earnhardt starter switch concept to next! News & photos to follow!
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I was able to get replacement relays for my Moto Guzzis for super-cheap through Digi-Key's website. Somebody else, who understands electronics better than I do, figured which ones worked. Here's the link in case somebody has the technical knowledge to figure out exactly what relay is needed:
http://www.digikey.com/
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OK. Here's something for starter relay welding victims to contemplate—a K75 starter relay (at least the part number of the one pictured at MAX, although with some additional suffix characters)—at an interesting price. Minimum order of two.
http://www.digipart.com/part/V23232A0001X005-EV-263
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The sticky starter relay is definitely a pain. I've tried everything, fresh batteries, super heavy duty battery leads (http://www.euromotoelectrics.com/Battery-Cable-Kit-BMW-K-BCK-5771317-p/bck-5771317.htm), 100% trickle charging, cleaned ground connectors and when I least expect it, it'll stick. Most often right after fueling up. I carry a spare relay, and both the installed and spare have been disassembled, had their contacts sanded and reassembled. In the last 10k miles I've probably only had it stick three times, maybe four. I carry a breaker bar in the tragkorb (with a socket for rear wheel changes) and I use that to whack the side of the relay box and un-stick the starter relay. I actually drew an X in silver Sharpie on my relay box so I'd know where to whack it :)
I direct line switch to the starter is a novel idea.
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I've heard about sticking starter relays, and I believe what I've heard about them, but I haven't had the issue. I've had low batteries turn the starter slowly before and have had a couple times where the battery was able to just turn it but stop, but still no fused relay
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What brand of breaker bar do you use, Tim?
It's a 24" 1/2" bar. Maybe Craftsman or Harbor Freight.
F14Crazy - Yeah, the relay sticking is not predictable on my bike. I've also had a low battery turn the engine slowly without the relay sticking, and I've had a strong battery cause the relay to stick. It's happened in cold and hot weather. Almost every time the relay stuck I was starting after a quick break after hard riding, like at a gas station or rest stop. It happened fairly regularly before the battery cable upgrade but not so much anymore. I also cleaned/overhauled the starter when I installed the new cables. (Easy job if you can get the screws out without stripping them.)
A couple of times I rode with the relay stuck / starter running for miles before I noticed something wrong. If you don't notice the starter's grinding noise over the engine sound the only other indication is that the lights and speedo are probably off (thanks to the load shed relay).
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TimTyler......did you experience starter relay problems on your cross-country trip? The unreliability of the K100/75 starter relay is so uncharacteristic of my long BMW experience.
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TimTyler......did you experience starter relay problems on your cross-country trip?
Couple of times that I remember.
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I hope this isn't going off topic but...
If you're on a trip or something and don't have access to a new relay, what can be done to work around the issue? Disconnect the starter and bump-start the bike?
I take it the starter relay is a sealed unit and you can't disassemble it and clean the contacts
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I was pointing out the reason why BMW chose a fragile starter relay - to implement a rider safety feature. There are other safety features of the bike including sidestand interconnects, sidestand switches on later models, neutral detect, and the bulb monitoring unit, all designed to make riding the bike safer. There's nothing to stop anyone who owns these bikes from defeating any or all of these safety features; in fact, it's often done.
Your idea of a SPST momentary toggle switch between a source of power and the starter. If you implement your circuit, you'd most likely connect the switch between the battery and starter, I assume, with a large gauge wire to give the maximum umph. Right?
There was a BMW service bulletin published in the mid-nineties that called for the use of a redesigned relay in police vehicles, I believe (Inge would probably know more). I am not able to find that bulletin online. It did not state exactly what the new relay did, but probably there was circuitry in the unit that stopped the contacts welding with a low battery condition.
F14, As for the starter relay, it's not sealed; it can be opened and serviced. Depending on how it failed will determine whether it is salvageable or must be replaced. In a pinch, you'd remove the relay from the relay box to stop the constant turning of the starter. Come time to get it going, it should be possible to bump start the bike.
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Could you just use like a jumper wire in place of the relay?
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It is no wonder these relays have problems. You connect a 300+ CCA battery to a set of contacts rated for 150A.
Here is an idea, replace the BMW relay with a real starter solenoid.
http://www.autozone.com/batteries-starting-and-charging/solenoid/duralast-solenoid/82182_0_0/?checkfit=true
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Yes, that will work! Little big to hide in the delay box, but I've managed to put lithium battery in the box. You could fit the solenoid , hide the lithium elsewhere.
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Could you just use like a jumper wire in place of the relay?
I was assuming that the relay had welded close. It would have to be isolated from the circuit to stop the starter from continuously turning. Was my assumption wrong?
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Could you just use like a jumper wire in place of the relay?
I was assuming that the relay had welded close. It would have to be isolated from the circuit to stop the starter from continuously turning. Was my assumption wrong?
Yeah...if the contacts weld the circuit would close and keep the starter spinning. But if you disconnect the relay and can't replace the relay like if you're on a trip can you use a jumper in place of the relay?
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If you are careful and have a couple of small jewelers screwdrivers and some 400 or 600 grit paper, it is possible to pop the case on the starter relay. Separate the contacts, and clean them up with a few passes of the paper. I don't know if you'll get another 50,000 miles out of them, but they should get you home.
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If you are careful and have a couple of small jewelers screwdrivers and some 400 or 600 grit paper, it is possible to pop the case on the starter relay. Separate the contacts, and clean them up with a few passes of the paper. I don't know if you'll get another 50,000 miles out of them, but they should get you home.
Doesn't hurt to keep some emery cloth on board
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I've had my k75 for approx 16 years .Just after I got it the relay stuck and the starter just kept cranking until the battery overheated & the side of the battery blewout.Battery acid everywhere lucky I had access to plenty of water.After it happened for the second time & I knew to disconnect the earth lead, resulting in one burnt finger.I have now fitted an in line battery isolator switch ( the smallest I could find).This has been fitted behind the side cover it required the cutting of the earth lead to accommodate the switch and soldering in two lug connectors.I can now isolate the battery and it can be used as a security device by removing the key.You can access the switch without having to remove the side cover.it is virtually invisible and would be even harder to see if you painted the removable switch black.Somebody else pointed out that he had a Ural which was fitted with one as standard. It was handy when you wanted to work on the bike & needed to isolate the electrics .I have posted pictures and installation instructions in the Workshop under Re: Starter relay stuck November 22nd.
Regards Martin
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Thanks, Martin, good tip. I'm headed to the Autozone store this afternoon to see what they got.
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Hey Robert & all - (Robert I have an ongoing thread over at K100-Forums that you have helped me with)
I am still unable to get my K75 running with the start button. The starter works great if I slap 12v to it right from the battery.
So, in reading this thread which I found very interesting - - I could essentially start the bike by merely juicing the starter itself? NOT to ride - as the bike is unfinished - I just want to start the ol' girl! The methods you guys are talking about is basically to skip the starter relay altogether, and go direct to the starter with a bounce switch like they have in race cars....so why couldn't I just hook up 12v to the starter nut and fire the bike up this way? Once it starts, I just let go of the jumper to the starter nut and thats it.
I also read online about splicing a ground to the frame, from the "starter relay control side ground" - - anyone know what terminal that is on the stock relay? Thanks everyone!
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I've had my relay stick twice but never had the contacts weld them selves closed. Maybe I was just lucky, but it annoyed me enough to fit a battery isolator switch in the earth cable.
Regards Martin
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So, in reading this thread which I found very interesting - - I could essentially start the bike by merely juicing the starter itself?
Yes, you could. This thread talked more about finding a way to bypass the starter relay to eliminate a known weakness in the K-bike electrics.
NOT to ride - as the bike is unfinished - I just want to start the ol' girl! The methods you guys are talking about is basically to skip the starter relay altogether, and go direct to the starter with a bounce switch like they have in race cars....so why couldn't I just hook up 12v to the starter nut and fire the bike up this way? Once it starts, I just let go of the jumper to the starter nut and thats it.
That is possible. I'd use a battery isolation switch to do the switching rather than freehanding a bare wire, just because of the current that will get drawn as the start motor runs under load.
I also read online about splicing a ground to the frame, from the "starter relay control side ground" - - anyone know what terminal that is on the stock relay? Thanks everyone!
You'd be looking for the Brown/Green wire on the two-pole white AMP connector that attaches to the relay coil. I'm not sure if this splice would hurt the ICU or not so, if you actually carry it out, I'd isolate the Brown/Green wire first and insert your own wire to ground. Remember that you'll not have any safety mechanism to prevent you from engaging the start relay even with the engine running whenever you hit the start switch.
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Robert, sorry but I do not have a brown/green wire anywhere near the starter relay.
http://www.motobrick.com/ducktech/kwiring/Early%20K75%20K100/K100_Early_Wiring_Diagram.jpeg (http://www.motobrick.com/ducktech/kwiring/Early%20K75%20K100/K100_Early_Wiring_Diagram.jpeg)
Perhaps you mean on a K100? Mine's a K75. If you could isolate the exact wire on the above diagram, that would be chipper!!!
Happy holidays to all.
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Sorry, I was writing from memory; obviously my memory is quite fallible. Should have referenced a schematic. It's Brown/Red.
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:clap:
Successfully grounded out the HES brown/red wire at the starter relay.
Bike is turning like a champ, but won't start. Plugs sparking, exhaust (no muffler yet) is getting fuel in it.
New strange behaviors....Will turn with bike in gear, or at least try to. Pulling in the clutch doesn't make a difference.
Thoughts...bad gas is a definite. I need to get fresh gas in there.
Plugs look okay but could be old, also couldn't hurt.
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Here is an idea, replace the BMW relay with a real starter solenoid.
http://www.autozone.com/batteries-starting-and-charging/solenoid/duralast-solenoid/82182_0_0/?checkfit=true
I'd like to try this.
Looking at this one http://www.colehersee.com/home/item/cat/187/24047/ They make a "marine" version of that too, maybe for mounting outside the relay box?
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Bike is turning like a champ, but won't start. Plugs sparking, exhaust (no muffler yet) is getting fuel in it.
Re the no start, I'd double check that the plug wires are correctly installed. This has tripped up more than one in a 'no start' condition after some repair work
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Tim,
Looking at the schematic of the bike, it looks like the starter relay is powered from the ignition control unit. I don't know what the current capacity of the ICU is, but I believe there are schematics of it's inner workings that may give an indication of what it can deliver. This current from the ICU is probably the determining factor on what relay can be used.
One option might be to use a heavier Bosch relay. I have stumbled across a 100 amp(vs the K bike 75A) that is a direct replacement. The price also looks pretty good at $29.97 from this place:
http://theelectricaldepot.com/relays/high-power-relays/power-relay-12v-spst-100-amps-br-1-each
Another option is to use a starter relay from a big v-twin rice burner. I have seen a number of relays on Amazon in the $10-12 range for bikes like the 1700cc Suzuki Boulevard that might work in our bikes with a few mounting modifications.
I'm thinking the key thing about a starter relay for our bikes is that with all the electronics this relay should have good suppression across the coil. For this reason, I think I am revising my suggestion for an automotive or marine solenoid. I don't feel comfortable with the suppression you would get with these devices, especially since seeing how the coil is connected to the ICU.
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One option might be to use a heavier Bosch relay. I have stumbled across a 100 amp(vs the K bike 75A) that is a direct replacement.
The amp ratings for both those relays looks the same to me: Resistive load Switching current/no. of operations A/Thousand 75 /≥ 125
0 332 002 150 (http://rb-aa.bosch.com/boaarocs/index.jsp;jsessionid=A42BD9E7561580A360494149963C1BD3.sundoro2?ccat_id=33&prod_id=113) vs 0 332 002 161 (http://rb-aa.bosch.com/boaarocs/index.jsp;jsessionid=A42BD9E7561580A360494149963C1BD3.sundoro2?ccat_id=33&prod_id=115)
150 has "twin contacts" and 161 has "single contact"
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I'm thinking the key thing about a starter relay for our bikes is that with all the electronics this relay should have good suppression across the coil. For this reason, I think I am revising my suggestion for an automotive or marine solenoid. I don't feel comfortable with the suppression you would get with these devices, especially since seeing how the coil is connected to the ICU.
The starter relay draws 350 mA from the ICU to engage. This small current draw is not much and is easily handled by the ICU's transistor output stage.
The key factor in reliable operation of the starter relay is not so much suppression of back-EMF in the coil, rather it's having good hysteresis (i.e. a marked difference between the pull-in voltage and the drop-out voltage). The relay will oscillate around its pull-in/drop-out voltage if the two are too close together in value, causing the contact welding we see. Bosch designed a 12V starter relay that uses a 6V coil and electronics that introduce hysteresis. This starter relay will pull-in close to 12V but hold even if the battery terminal voltage drops to 10V (typical for a worn battery) once the engine starts cranking.
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.... Bosch designed a 12V starter relay that uses a 6V coil and electronics that introduce hysteresis.
Thanks, Robert. Is that the 0 332 002 161 OEM relay?
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Here is an idea, replace the BMW relay with a real starter solenoid.
http://www.autozone.com/batteries-starting-and-charging/solenoid/duralast-solenoid/82182_0_0/?checkfit=true
I'd like to try this.
Looking at this one http://www.colehersee.com/home/item/cat/187/24047/ They make a "marine" version of that too, maybe for mounting outside the relay box?
yeah I was thinking of just like a generic old Ford starter solenoid. Least if it went bad on the road you could get one at any auto parts store or salvage yard. Hell with those Fords you can just put a screwdriver across them
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F14, The problem with automotive relays is that their coils draw about 3 amps. As Rob points out, the Bosch relay coils only draw 0.35 amps.
It might be possible to drive an automotive relay with a small relay which is driven from the ICU. This would allow higher current handling contacts to be driven by the low power output of the ICU.
Rob, Hold-in on the automotive starter relays is usually somewhere in the range of 5-6 volts, so drop out shouldn't be an issue. As far as the rating of the 161 relay, the model designation is for 100 amps vs. the designation of 75 amps for the K relays. I would have to think that the difference would relate to an ability to handle higher currents that may not show in the specs.
I haven't researched them, but there are a few Suzuki and Yamaha relays that look like they may be good replacements for the Bosch units. What has caught my eye with them is their price which is in the $10 range. Perhaps the coil current is low enough on these relays that they could be wired directly to the start button avoiding the ICU. Unfortunately, there are no readily available specs for any of these relays, and I don't have the time right now to look for them.
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F14, The problem with automotive relays is that their coils draw about 3 amps. As Rob points out, the Bosch relay coils only draw 0.35 amps.
It might be possible to drive an automotive relay with a small relay which is driven from the ICU. This would allow higher current handling contacts to be driven by the low power output of the ICU.
It may seem counterproductive but can you drive an automotive relay with the stock relay? The stock relay should last forever in that case
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It may seem counterproductive but can you drive an automotive relay with the stock relay? The stock relay should last forever in that case
I was thinking this too. Although since my stock relay has been arc'd and welded a couple of times, it might make more sense to swap it out with a cheap, low amp relay.
I was also thinking, regarding the original post, that if one did just hardwire a switch to the starter (bypassing the starter circuit and relay) wouldn't the rider need to depress the handlebar starter switch AND the new starter switch to get the bike going? The old starter circuit still needs to activate the fuel pump and other stuff, right?
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You're right, it looks like the start button signal is routed through the ICU to energize the start relay. I like the idea of having the original relay energize the external one. Saves the contacts and isolates the inductive kick from the external relay.
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Do the factory style relays go bad often enough? I have at least 30k worth of starts on mine and no issues yet
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Thanks, Robert. Is that the 0 332 002 161 OEM relay?
I can't say for sure. I remember picking up this tidbit of info during my forum reading. The info came from BMW Service Bulletin 12 001 01 (023) (http://www.maxbmwmotorcycles.com/fiche/NotesParts/61357663945_1.pdf).
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I had two relays in 60k miles and they have stuck maybe 20 times, probably more. I've tried everything I could except new starter motor bearings, and i just ordered those.
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I had two relays in 60k miles and they have stuck maybe 20 times, probably more. I've tried everything I could except new starter motor bearings, and i just ordered those.
Haven't had one stick yet. My previous battery was weak for a while and it ran out of juice and stopped turning the starter but no stuck relay :dunno
I should check on my relay though. Knowing that this was owned by Drake I have little doubt that it's not OEM
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This Honda PDF (http://www.hongfa.com/pdf/EXPLANATION%20TO%20TERMINOLOGY%20AND%20GUIDELINES%5CExplanation%20to%20terminology%20and%20guidelines_General%20relay_en.pdf) has a lot of info on relays and relay terminology.
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You're right, it looks like the start button signal is routed through the ICU to energize the start relay.
The power from the start button goes directly to the relay coil, and the relay coil is grounded by the ignition
ECU as long the rpm is lower than 711.
About the starter relay reliability......my oldest K have past 200K km, never had any problem with the relay.
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Do you guys have ground wires connected to your starter motor mounting screws? I don't.
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That's a K1100 / Motronic thing. It's not present on classic K's with Jetronic.
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Installed the Starter Overhaul Kit (http://www.euromotoelectrics.com/Starter-repair-kit-for-Denso-Starter-BMW-K-p/bmw-strk007tk.htm) from EuroMotoElectrics today. Found that my brushes were a little short and the armature contacts were very dirty. Cleaned the commutator contact area up with brake cleaner using a toothbrush & rag.
The brushes on the EuroMoto kit are configured differently than the OEM brushes in a way that makes them harder to install. Basically, they must be held in place when reassembling the starter. Took me forever. Would have been easier if I had three hands.
The terminal screw on the Denso brush set is also a little shorter than OEM. I chose to use my existing insulating plastic brush set pieces, so there's barely enough threads for the terminal tightening nut to hold the cable from the relay on.
When I was removing the old ball bearing assembly I chipped off a tiny piece of that ultra-hard plastic coating covering the armature wire wrap. Not sure what the plastic coating is for, but I assumed it's insulation. Filled the gap in with a glue gun, hoping :dunno
Once reinstalled the starter get's the motor running quickly.
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That is a lot of technical hassles for a remove & replace component, apparently related to a minor discrepancy in specs. Lesser folks would not have resolved as you did. I shudder to think about it..... Do our friends at EUro get feedback on this? They have been a good source to me, but I don't know if I would have figured out a problems like this. Good work Tim! No wonder you aren't fazed by starter relays like the rest of us!
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But my K100 project is a non-stock project that I am going to apply my Dale Earnhardt starter switch concept to next!
Excuse my ignorance, but what is a Dale Earnhardt (RIP) starter switch?
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That refers to the starter button Dale Earnhardt Jr. Uses on his race car. I got frustrated with multiple burnt starter relays and figured out just running the starter with a race car starter button. It's the gold thingy in the picture.. no key no relay.
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I love that! What do you do for security...a U-Lock for the wheels? This seems like a cool idea honestly.
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Security? line of sight plus Glock .40 cal
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:clap:
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:2thumbup:
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I was researching relays for a friend around another subject and came upon an interesting unit that could be used to replace the generally expensive and unreliable OEM starter relay.
Problem: When the battery has a low charge, attempting to start the bike could result in a damaged starter relay, with the consequence that the engine will continue to turn over until the battery is drained or it overheats and gets damaged. The reason is because the low battery voltage combined with the high cranking current causes the relay’s contacts to weld together.
Solution: I found a high current (120A/12V) contactor on Aliexpress that appears very promising as a replacement for the OEM starter relay. What is the difference between a contactor and a relay? The starter relay in the K-bike has a single pair of contacts through which all current flows when cranking the engine.
(http://www.surplussales.com/Images/Relays/Contactors/ko-prd3dy012_lg.jpg)
As shown in the image above, a contactor has two pairs of contacts through which current flows, spreading the load across four contact pads, and being less likely to heat up and weld together. Furthermore, the actuator arm consists of a bar with the contacts at both ends. When the contactor is turned off, both contacts break, with a more positive cut in current flow. Contactors are commonly used in high power switching applications.
The contactor I found has a very small package – just 42mm X 42mm X 42mm in size. There are two ¼” spade terminals for connecting the coil leads and two M6 studs for connecting the starter battery and motor leads. The pickup voltage is 7.8V and release voltage is 1.2V. This low pickup voltage and broad hysteresis (difference between the voltages) means the contactor is not as susceptible to oscillation as is the OEM starter relay. The main contacts are rated at 120A and the maximum power handling capacity is 1680 W (about 2.2 HP), more than enough to handle the current drawn which cranking the engine. The price is also very attractive at around US$12 each; cheaper in larger quantities.
http://www.aliexpress.com/store/product/200a-starter-relay-automotive-relay-contactor-relay-12v-24v/346626_1649592976.html?spm=2114.12010108.0.78.eRhDCI
(http://g03.a.alicdn.com/kf/HTB1F.8iIXXXXXb4XFXXq6xXFXXXj/120a-starter-relay-automotive-relay-contactor-relay-12v-24v.jpg)
My friend will be ordering some so if he can spare one, I’ll try it out in my K75 to see how it works.
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Interesting.
I wonder if that's the same as this (http://amzn.to/23rXfbx) or this (http://amzn.to/20rwXUk) or this (http://amzn.to/1WN4XrY)on Amazon?
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It might very well be the same, Tim. I'm sceptical at the moment though. The advertizing copy states that it is a contactor, however without having pictures of the components inside of the package and being from China, this is only marketing hype for the moment. And what about electrical ratings; are these peak values or continuous values? I'd love to get my hands on one of these bad boys and dissect it.
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If these alternative relay or solenoid options require more current from the ECU to connect the battery to the starter than the Bosch relay, will the ECU be damaged or will the relay/solenoid simply fail to connect the starter?
The Bosch/Tyco relay on EME's site is listed as " ...with resistor / diode to prevent voltage spikes potentially damaging the Engine Management System Control Unit (ECU)". Is that a real concern?
Like.... how dangerous is it to experiment? :dunno Inge?
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The pickup voltage is 7.8V and release voltage is 1.2V. This low pickup voltage and broad hysteresis (difference between the voltages) means the contactor is not as susceptible to oscillation as is the OEM starter relay.
What's the relationship of the low pickup voltage of 7.8V to the intermittent work value on the spec sheet of the aliexpress item?
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You can replicate the flyback diode or 'snubber' to another relay if not present. However it is critical to prevent ECU damage.
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You can replicate the flyback diode or 'snubber' to another relay if not present. However it is critical to prevent ECU damage. Another concern would be how much current the ECU can source to the relay coil.
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The pickup voltage is 7.8V and release voltage is 1.2V. This low pickup voltage and broad hysteresis (difference between the voltages) means the contactor is not as susceptible to oscillation as is the OEM starter relay.
What's the relationship of the low pickup voltage of 7.8V to the intermittent work value on the spec sheet of the aliexpress item?
Initial current to pull in the contactor is the intermittent rating, To maintain the contactor is the continous rating.
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Initial current to pull in the contactor is the intermittent rating, To maintain the contactor is the continous rating.
How does the 7.8V fit in the equation, Bill?
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They relay or contactor will 'pull in' or engage at 7.8 Volts. Useful if the terminal voltage while cranking drops.... depending on the starter load some vehicles will drop to 9 volts when the starter engages, hence ECUs typically can work at 7 Volts. Caterpillar for instance specs their ECU at 6.5 when starting a big diesel. No point in cranking if the ECU and injectors are dead due to low voltage. Remember that a DC Brushed motor at start is much like a short circuit.
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Thanks for the explanation, Bill.
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Hope it helps ..... The original circuit has a reasonable tolerance for age and wear. Redesigning it to make up for other components past their due date, ie a tired battery or a fuel/ignition system that won't fire up readily. The uncontrollable part is the operator that holds the starter engaged for a long time. The starter motor is not designed for continuous duty.
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I've only ridden mine 1/4 mile [bought it New Years Eve in Ontario]. A spare relay does seem like a good idea though .....
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It was a great quarter-mile though, wasn't it? :clap:
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Had not swung a leg over in 25 years but I was hooked all over again !
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If these alternative relay or solenoid options require more current from the ECU to connect the battery to the starter than the Bosch relay, will the ECU be damaged or will the relay/solenoid simply fail to connect the starter?
The OEM starter relay sinks 546 mA into the ECU when operating and measures 19.1 Ohms across the coil. The contactor I mentioned measures between 30 Ohms to 60 Ohms across the coil. That's means this contactor will demand almost 1/3 less current compared to the OEM relay. This contactor puts less load on the ECU drivers.
The Bosch/Tyco relay on EME's site is listed as " ...with resistor / diode to prevent voltage spikes potentially damaging the Engine Management System Control Unit (ECU)". Is that a real concern?
Like.... how dangerous is it to experiment? :dunno Inge?
As Bill mentioned, it's probably not a bad idea to put a snubber circuit across the relay coil to reduce EMF spikes that could take out the ECU. Those spikes are not necessarily generated by the relay itself. They might come about through the clutch switch.
What's the relationship of the low pickup voltage of 7.8V to the intermittent work value on the spec sheet of the aliexpress item?
As Bill also mentioned, it is the voltage at and above where the armature remains engaged. Tim linked earlier to a good document that describes Honda relays. The following is taken from that document:
Operate (pickup) voltage is the voltage which closes the NO contacts when the relay is in the releasing state and coil voltage
is gradually increased.
Release (Dropout) voltage is the voltage which closes the NC contacts when the relay is in the operation state and the coil voltage is gradually reduced.
(http://www.motobrick.com/index.php?action=dlattach;topic=7704.0;attach=13532)
That spec sheet clipping you posted looks to me to be part number variants, depending on whether you want a relay spec'ed for intermittent use (4.8W) or continuous use (2.4W). Those values get tacked onto the manufacturer's part number. I don't think they represent power figures.
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That spec sheet clipping you posted looks to me to be part number variants, depending on whether you want a relay spec'ed for intermittent use (4.8W) or continuous use (2.4W). Those values get tacked onto the manufacturer's part number. I don't think they represent power figures.
That clipping was part of the data sheet supplied via your link to the page for ordering the part, Robert. There doesn't seem to be any part offered other than that $12.34 part; those specs were published with it. Among the "dash numbers" there is one 12V for continuous and one 12V for intermittent but the only qualifier in the text is that if a 24V application is wanted, it should be specified when ordering. Is this part rated for both continuous and intermittent use?
To summarize my understanding and rephrase your previous observation: Is it fair to say that the advantage of this part is that if it gets only 10V instead of 12V it's probably not going to operate at all or if it does, it's not going to supply enough current to weld the contacts because the current is crossing four points rather than two. What is the outcome if it can't bridge the gap at all? Just search only for a charged battery instead for a charged battery and a new relay?
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... the espresso maker
I switch to Turkish coffee on the road. No machine and uses less water. Oh, and very fast to brew.
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Here is the old type starter relay along side the newer version, rated the same, but manufactured under license from Bosch. Note the dual contacts and heavy braided copper connecting wires.......bet this won't burn out or weld. Got it from Euromotoelectrics in Denver.
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I was researching relays for a friend around another subject and came upon an interesting unit that could be used to replace the generally expensive and unreliable OEM starter relay.
Problem: When the battery has a low charge, attempting to start the bike could result in a damaged starter relay, with the consequence that the engine will continue to turn over until the battery is drained or it overheats and gets damaged. The reason is because the low battery voltage combined with the high cranking current causes the relay’s contacts to weld together.
Solution: I found a high current (120A/12V) contactor on Aliexpress that appears very promising as a replacement for the OEM starter relay. What is the difference between a contactor and a relay? The starter relay in the K-bike has a single pair of contacts through which all current flows when cranking the engine.
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My friend will be ordering some so if he can spare one, I’ll try it out in my K75 to see how it works.
Any news on this? Im looking forward to your results.
3rd time in a short period that i had a stuck relay, and im not gonna pay for a new crappy one.
What will you do with the 2 bits of electronics that are in the relay, i believe a resistor and cap, to prevent spikes on the ECU.
Last weekend i tried to replace the solenoid with a chinese 100Amp DC solid state relay i had. But i couldn't get it to run for some reason.
Actually i couldnt even detect a voltage on the ignition "activation wires" when i pressed the ignition, any ideas?
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Any news on this? Im looking forward to your results. ... What will you do with the 2 bits of electronics that are in the relay, i believe a resistor and cap, to prevent spikes on the ECU.
No news yet as I haven't talked to him in a while. As for the resistor/cap, I'll not be substituting for them if the contactor doesn't have similar; just see how it goes.
Last weekend i tried to replace the solenoid with a chinese 100Amp DC solid state relay i had. But i couldn't get it to run for some reason.
Actually i couldnt even detect a voltage on the ignition "activation wires" when i pressed the ignition, any ideas?
Did you source a SSR designed for DC loads? If you did manage to get it to work, it probably would have quickly self-destructed with the continuous pounding it receives from the inductive load of the starter motor. SSRs don't handle large back-EMF well. In this application, a mechanical relay beats a SSR.
BTW, did you connect the polarity of the input correctly. SSRs use a LED in the control circuit and you need to observe and respect the polarity.
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Solid state relays can be of 2 varieties ..... a power mosfet or triac. A link or part number would help us figure out what the problem is :dunno2:
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Arnnonymous fit a isolator switch in the earth lead, I have posted pictures and installation instructions in the Workshop under Re: Starter relay stuck November 22nd. It doesn't cure the relay problem, but it makes for a quick disconnect. it has other advantages as well, read the post.
Regards Martin.
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Did you source a SSR designed for DC loads? If you did manage to get it to work, it probably would have quickly self-destructed with the continuous pounding it receives from the inductive load of the starter motor. SSRs don't handle large back-EMF well. In this application, a mechanical relay beats a SSR.
BTW, did you connect the polarity of the input correctly. SSRs use a LED in the control circuit and you need to observe and respect the polarity.
Yes i watched the polarities, but had to guess on the "switching" side. Well reading up more it seems like 100amps is not enough anyway. So iguess it died.
I will fit a quick kill switch but would like a good relay. And was hoping a ssr would work
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My starter relay stuck again yesterday.
Today I installed the Cole Hersee solenoid (http://www.colehersee.com/home/item/cat/168/24047/) that I bought earlier in this thread. It works!
Of course, the old starter relay is still in the chain but it's using a lot less voltage so hopefully it won't lock-up anymore. I was just thinking that I should install an on/off switch between the Bosch and Cole Hersee in case the Bosch sticks which might damage the solenoid. I wonder how much voltage the solenoid draws?
The large terminals on the Cole Hersee solenoid are wired directly to the battery and starter motor as expected. One of the small solenoid terminals is wired to GROUND (14 AWG) and the other to the Bosch relay terminal 87.
The large Bosch relay terminal 30 is wired (14 AWG) directly to the battery. I was wondering if I should add a fuse here?
The other large Bosch terminal 87 is wired to one of the Cole Hersee solenoid small terminals (as mentioned above).
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Congratulations, Tim, that set-up should work for sure. Not sure why a fuse in the link to Bosch terminal 30 would be advantageous, seems that creates a weak link for blown fuses. The Bosch should handle the 12v input fine, its 75a rated. But I may be missing something......if a solenoid handles the starter load, why does the Bosch relay still need to be in the system? Why can't starter activation go directly to the solenoid?
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Why can't starter activation go directly to the solenoid?
The Bosch has a diode that protects the ECU from voltage spikes, I think. (Discussed earlier in this thread) (http://www.motobrick.com/index.php/topic,7704.msg56338.html#msg56338)
I don't know enough about diodes to replicate that functionality without the Bosch.
Sure would be nice to get rid of the Bosch all together though. Space is tight in that relay box!
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Nor do I know about said diodes & voltage spikes........I wonder how the generation of voltage spikes occurs, the magnitude, and whether the system is so sensitive as to loose starter relay/solenoid function. Sounds like its time for a tutorial by Brother RBM.
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I remember... There was some question as to whether or not the voltage necessary to switch the Bosch would be enough to switch the larger solenoid. The Bosch apparently only requires a little juice to do its job.
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Now that makes sense............the low feed to activate the Bosch relay.......little in, large out.........might well be insufficient to activate the solenoid, hence a "step" relay. Would be interesting to look at actual values, cause theoretically, a relay should not be nesessary to activate a solenoid. Get RBM on the numbers!
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Nor do I know about said diodes & voltage spikes........I wonder how the generation of voltage spikes occurs, the magnitude, and whether the system is so sensitive as to loose starter relay/solenoid function. Sounds like its time for a tutorial by Brother RBM.
The voltage spikes occur in the reverse polarity of the applied coil voltage.
- 12 volts applied to the coil causing a magnetic field.
- Armature moves making the contact closure between 30 and 87
- Remove coil voltage, the magnetic field collapses, and induces a voltage in the coil
- Because the magnetic field is now moving in the opposite direction, the voltage polarity is reversed
[ii]The diode in parallel with the coil is oriented to conduct with the reversed polarity effectively shorting the induced voltage to ground[/li]
[/list]
As i have yet to venture hands on into the circuit rbm will have the best applied knowledge.
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Nor do I know about said diodes & voltage spikes........I wonder how the generation of voltage spikes occurs, the magnitude, and whether the system is so sensitive as to loose starter relay/solenoid function. Sounds like its time for a tutorial by Brother RBM.
Bill is correct. When a relay coil is de-energized, the sudden collapse of the magnetic field will induce a reverse potential (i.e. opposite polarity) voltage spike in the circuit proportional to the rate of collapse. There is a lot of energy in this high voltage spike which must be dissipated. The energy wants to dissipate across the transistor in the ECU that shut off the current to the relay (think of arcing that occurs in the switch when you shut off a light), thus destroying the transistor. If a high speed diode is placed across the coil, when the voltage spike occurs the diode causes a short circuit across the relay coil. The energy is captured inside the relay coils where it dissipates it as heat, thus protecting the transistor in the ECU. This is called a snubber circuit.
Selecting the diode is straightforward. Use a switching diode with about 400V - 600V reverse voltage and 1 Amp, like a common 1N4007.
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Excellent explanation...........I knew you could take us to school. But how could the solenoid be employed without relying on the starter relay in the circuit?
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The solenoid could work alone if the characteristics of the device doesn't exceed the capabilities of the ECU to drive it. Afterall, a solenoid is just a large capacity relay in a different form-factor. I'm talking about the operating voltage and current of the solenoid's coil. The current draw of the solenoid shouldn't exceed 550mA and the pull-in voltage should be minimum 8V-9V.
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Thanks, guys. I've put a call into Cole Hersee to get some specs.
So just one these diodes (http://amzn.to/1psJwRU) then?
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Now, Tim.......just wire the solenoid direct and see if it blows the ECU, then we'll know. Where is your sense of adventure?
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Thanks, guys. I've put a call into Cole Hersee to get some specs.
Doesn't it seem that your intermittent duty solenoid may be drawing current in excess of Robert's observations according to one of the FAQs here (http://www.colehersee.com/home/faq/faq/solenoids/), Tim?
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Thanks, guys. I've put a call into Cole Hersee to get some specs.
So just one these diodes (http://amzn.to/1psJwRU) then?
Yes, Tim. But that's exorbitantly expensive. That should be the price of 25 of these diodes. These are commonly available at any local electronics supply or online at Digikey or Mouser.
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Doesn't it seem that your intermittent duty solenoid may be drawing current in excess of Robert's observations according to one of the FAQs here (http://www.colehersee.com/home/faq/faq/solenoids/), Tim?
Sadly, it does :(
How much current does the control circuit in a solenoid draw?
Generally, the control circuit for a continuous duty solenoid rated at 12V DC draws about 0.70 of an ampere.
The control circuit for a 24V DC continuous duty solenoid draws about 0.34A.
An intermittent duty 12V DC solenoid draws about 2.73A, and the 24V DC about 0.83A.
I suppose I could replace the Bosch with a much more compact, lower amperage relay.
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These are commonly available at any local electronics supply or online at Digikey or Mouser.
The last local electronic supply store within 40 miles of 98501 went out of business a few months ago!
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Selecting the diode is straightforward. Use a switching diode with about 400V - 600V reverse voltage and 1 Amp, like a common 1N4007.
Assuming I switch out the Bosch for a smaller, possibly more reliable relay, and knowing that the solenoid draws up to 3 amp, I assume the 1-amp 1N4007 will be under-rated?
Would I need a switching diode rated for 3 or more amps?
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Assuming I switch out the Bosch for a smaller, possibly more reliable relay, and knowing that the solenoid draws up to 3 amp, I assume the 1-amp 1N4007 will be under-rated?
Would I need a switching diode rated for 3 or more amps?
No, you won't. The diode only conducts when the power is removed, otherwise it is effectively not in the circuit. So, it is sized to handle the spike's energy for only a few milliseconds. Don't forget to install the diode in reverse - anode to ground, cathode to +ve.
(http://www.accessconnect.com/images/diode_relay.jpg)
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Thanks, Robert!
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Here is the old type starter relay along side the newer version, rated the same, but manufactured under license from Bosch. Note the dual contacts and heavy braided copper connecting wires.......bet this won't burn out or weld. Got it from Euromotoelectrics in Denver.
So i've taken out my K-bike out of winter storage. The battery is strong and full.
I smoothed out the contacts of the Starter solenoid with some sanding paper.
And out of 10 times starting, it stuck around 3 times.
It releases quite easily(with a hit at right spot), but i had it once before also while on the road at night, which is less fun as all the lighting turns off.
I want to really solve this for good.
In this thread two alternative solenoid are discussed, one from Aliexpress and one from Littlefuse.
I cannot easily obtain the littlefuse here in NL.
I would like to obtain the original one mentioned by TrueAce, unfortunately this one is not easily obtained as well.
So for now i will try aliexpress. The one posted by RBM sells in 120A and 200A forms.
(https://nl.aliexpress.com/item/car-relay-12v-200a-auto-starter-relay-with-24v-200a-red-copper-terminals-auto-control-system/32269200596.html (https://nl.aliexpress.com/item/car-relay-12v-200a-auto-starter-relay-with-24v-200a-red-copper-terminals-auto-control-system/32269200596.html))
Would it be a good idea to get the 200A one? If i use the stock starter to engage a second (new solenoid) i wouldn't need the diode spike thingy over the new solenoid contacts right? as the ECU is already protected at the first solenoid, am i right?
I will see if i can move the diode from the old solenoid to the new, once i know the new one works well.
[edit] Whoops something went wrong there.
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just browsed this thread for the first time. Always heard of the solenoid fusing but despite my share of low batteries never experienced it. Like the idea of a cut off switch on the ground wire, would come in handy for lots of things. Of course, I've jinxed myself now.
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So i got the chinese 200A one, and last weekend installed it.
https://nl.aliexpress.com/item/car-relay-12v-200a-auto-starter-relay-with-24v-200a-red-copper-terminals-auto-control-system/32269200596.html (https://nl.aliexpress.com/item/car-relay-12v-200a-auto-starter-relay-with-24v-200a-red-copper-terminals-auto-control-system/32269200596.html)
I took out the old one, removed the internal protective resistor that is over the triggering lines.
And soldered it to the new relay.
visually the Chinese one looks much better specced than the original, and it works well so far.
for € 15 im happy with it.
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I really appreciate this thread. :clap:
I recently picked up a second K75, '88 with 9K on it. I rode 4 days home with no problems. The following weekend I go to move it, and it won't turn over (brand new battery) and starter keeps going like it's possessed.
Now I've owned my '87 K75 for 18 years and 105K miles and I've never had this problem! What I'm learning is it may very well be related to the '88 having sat for many years.
I'm not sure this is a DIY project, electrical is not my forte.
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The following weekend I go to move it, and it won't turn over (brand new battery) and starter keeps going like it's possessed.
So,SheRider,the starter motor ran but the combustion motor didn't turn over?Look up "sprag clutch" as well.(if this is indeed what happened.)
The electrical jammed on starter motor,as well,is just darned unlucky and a bit odd being a new battery and the starter would not have been drawing the high amps that a welded solenoid contact would need,it being not engaged with the engine.My eyes would also be looking at that green starter knob sticking as a long shot.
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Easy Sprague clutch fix no drilling involved. http://k-bike-knowledge.000webhostapp.com/mechanical/sprag_clutch/starter_clutch.htm
Regards Martin.
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Worth knowing that method to be sure,Martin,of course no moly slip in the engine oil is nessesery.That can cause this slipping,also short trips.My mate did all this on his brick.We dug right into his and got it out the hard way and deglazed that surface(short commuter trips)20 odd years ago.I bump start mine when the battery is suss to avoid the dreaded whirling durbish latching on and ever running.
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One of the best mods I've done on my brick is an isolator switch in the earth lead. I've had a battery blow out it's side due to relay contacts welding. Isolator switch is also handy when you need to isolate the battery when doing work. Also handy as a anti theft device especially if you remove the key or paint the key black. there is a post on how to do it.
Regards Martin.
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I'm not sure this is a DIY project, electrical is not my forte.
I understand from what I'm reading here your bike's symptom is the starter's spinning uselessly when the button is pushed but the engine is not turning over. When the button is released, the starter and its spinning howl cease. Is that it? If so, electrical knowledge isn't needed, yet.
Here's a thread describing the situation, if you haven't seen it already.
http://www.motobrick.com/index.php?topic=2547.0 (http://www.motobrick.com/index.php?topic=2547.0)
Following the guidance diligently in the link below should get you out of trouble. Your bike doesn't have thousands of mile of accumulated crud in it. I roll start my bike in third gear.
http://bmwmotorcycletech.info/kstartersprag.htm (http://bmwmotorcycletech.info/kstartersprag.htm)
When you add the Rislone or CD2, you don't want to exceed the maximum level in your sight glass so let some oil leak out into a pan by loosening the drain bolt then add the treatment. If, after the first treatment didn't work, I'd do a second by draining all the oil, adding Shell Rotella diesel oil and some Rislone and do it again. I'd enjoy the ride, too. If that didn't fix it there's the following.
Just before disassembly to remove and clean the sprague clutch itself, there's this exciting procedure but it isn't for the faint of heart.
https://www.motobrick.com/index.php/topic,5933.0.html (https://www.motobrick.com/index.php/topic,5933.0.html)
Some members here have chosen to use high-detergent diesel oil like Rotella as a means of warding off future sprag sticking. I think engine flushing will work for your bike given its condition.
If you want to go the full mechanical distance, there's this.
http://www.k100-forum.com/t4116-sprag-clutch-cleaning-the-sprag-clutch-and-bearing-replacement#41210 (http://www.k100-forum.com/t4116-sprag-clutch-cleaning-the-sprag-clutch-and-bearing-replacement#41210)
Like already wrote, I think you'll fix it with the flushing method, that is, if I've understood the point of your query from its beginning.
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Full explanation on how the Sprague clutch works, and how to fix without drilling holes.
http://k-bike-knowledge.000webhostapp.com/mechanical/sprag_clutch/starter_clutch.htm
Regards Martin.
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. . . and how to fix without drilling holes.
That about finishes covering all the bases, SRAB. You'll fix this thing sooner than later. Please keep us updated.
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My apologies for disturbing an old thread.
I do so because 1. It is on topic and 2. It is the principle search result I get on the topic.
Here is my experience and my contribution:
1. This thread documents people with recurrent issues with the starter/relay system and other that have never had an issue.
2. I have two K75's one that has never had an issue, even with low batteries and another that continues to have the problem intermittently even though I have applied all of the "fixes" just as others have (replaced starter, cables, batteries and I think I am on relay number 5 now).
3. I attempted to replace the stock relay with one from an F650GS. This worked for a time but then I had a failure of the Ignition Control Unit. I assume this is related to the non-stock relay.
4. My current attempt at a solution I have just implemented, we will see if time bears it out. I put an original relay into the bike and use it to throw a second relay the F650GS relay. In this way I hope to have a starter relay that can handle the amps of the starter circuit and a relay that makes the back side circuit happy also. I had to run a line from the battery to the original relay to provide power to activate the second relay.
As a bonus all of this fits nicely into the under-tank relay box.
Again my apolitgies for posting in an old thread, this was the best place I could find for it.
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My apologies for disturbing an old thread.
1. This thread documents people with recurrent issues with the starter/relay system and other that have never had an issue.
These threads aren't buried and you aren't exhuming them, bmwcyclist. There are a couple of starter issues here. Which is yours?
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These threads aren't buried and you aren't exhuming them, bmwcyclist. There are a couple of starter issues here. Which is yours?
Thank you.
I am confused by your question, did I not document my post well?
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I am confused by your question, did I not document my post well?
If you're referring to Post #113, I didn't understand which type of symptom you were addressing—a starter that engages with the crankshaft but then continues to spin after the engine starts, a starter that doesn't respond, a starter that spins but doesn't engage with the crankshaft, or something else.
I might have been distracted by my mourning the passage of summer and tears were blurring my vision.
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I apologize for not being more clear.
I am addressing the Orginal Poster/Post Topic the problem with relays fuzing and how to engineer a work-a-round:
"Starter Relays appear to be among the TOP topics of discussion......really, just look at all the posts! Does the concept of the most critical link in the starter system "fusing contacts" every time there is lower battery amperage, or a random ground, seem right? Yeah, I know it's a 30 year old bike, but really, is there a more vulnerable electric component in a K75/100 than the starter relay?
After too many failures & replacements ($), I am thinking there is a way to re-engineer the starter system to fuction without an expensive Bosch relay...."
If you're referring to Post #113, I didn't understand which type of symptom you were addressing—a starter that engages with the crankshaft but then continues to spin after the engine starts, a starter that doesn't respond, a starter that spins but doesn't engage with the crankshaft, or something else.
I might have been distracted by my mourning the passage of summer and tears were blurring my vision.
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UPDATE/CHECK IN
It has not been two months of daily riding and I have had ZERO starter relay problems with the new twin relay setup!
This is by far the longest I have gone with this bike and not have a relay stick.
.