MOTOBRICK.COM
TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Jethroww on June 02, 2022, 09:29:13 PM
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Hi. I bought 1988 K75S in April 2017. 76500 km on engine. Ran fine for 1 minute then loud banging from engine.
Found a used black engine 1990? with I think was told 110,000 km on it. Installed the engine and ran fine until
last year. While driving it would just stop running. No misfire no fuel problems just completely stop for a
second or 2 and then just start running again like nothing had happened. This happened a few times last
year. Then in September it just completed stopped running at around 80 km per hour. Trying to jump star while
I was slowing down nothing. Trying to start nothing. Rolled to stop and started to check fuses etc. Thought it
might be fuel pump because I didn't hear it running. After about 40 min of checking and not finding anything
I tried to start the bike again. After the second attempt I heard the pump running after I let go of the start button.
2 more tries and it started up. Drove home with no problems about 25 Kilometers. Did some research and
thought it might be the Hall sensor. Started the bike up and let it idle for about 30 min. The second time it
just stopped and would not start back up. Tried starting it a few more times different days and it wouldn't start.
Last October ordered a new Hall sensor from Euro Motoelectrics. Replaced it this April. Started up after a few tries.
Starting using the bike as my daily driver in May. Then May 12 after work 4pm tried starting and gas just dripping of
exhaust pipe. Checked over bike no problems found. Pulled #7 fuse and bike started up but died. Put all riding gear
back on and got the bike running with fuse back in. Kept the rpm around 3,000 and started my ride home about 84 Kilometers. Stalled 1st time for a second and then started back up. 2nd time was about 10 Kilometers later and
took about 4 attempts at starting to get it running. With keeping 3,000 rpm at stop lights made it home in about
90 minutes. Bike idled fine. Started back up ok. After research cleaned the coolant temp sensor wire connection
and ignition switch with Deoxit 5.
Drove it for about 45 min with no problems stopping and starting back up. Thought I fixed the problem. Monday
morning on my way to work about 17 Kilometers from my place the bike just completely stopped again. Same
thing as happened last September. Waited about 15 min tried starting and 3rd attempt it started back up. Drove
back home with no problems. Have put about 800 Kilometers on this Hall sensor. I have new plugs and wires
NKG (DR7EA). I don't think they are the problem. The bike now has 134,000 Kilometers on it. So I have put
about 56,000 Kilometers on this engine. Any help in what could be causing this problem is greatly appreciated.
Thanks Jethroww
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Electrical issues of a spurious nature like that can be very difficult to solve.
The first bit of advice to come from the regulars of this forum will be to unplug and clean all the connectors
giving special attention to the ground point on the frame under the tank.
You actually want to have a permanent "no start" situation in your garage so you can identify the source.
rbm will hopefully chime in. He's the best electrical guru and is also somewhere in Ontario.
Good luck.
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You may have multiple problems. First thing that came to mind as I read your tale of woe was, "have you cleaned the ignition switch?"
If you do a search here you will find a write up on how to do it.
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Hi. I bought 1988 K75S in April 2017. 76500 km on engine. Ran fine for 1 minute then loud banging from engine. Found a used black engine 1990? with I think was told 110,000 km on it.. . . The bike now has 134,000 Kilometers on it. So I have putabout 56,000 Kilometers on this engine.
I can't understand how you arrived at the final total kilometers using the figures that preceded it. Did you leave off telling us the mileage of the bike when you swapped in the replacement engine? Nevertheless, have you replaced the fuel filter? When it quit the first time and came completely to a stop, did the dash lights shut off? When the bike wouldn't jump start or start up, do mean you could crank it and it wouldn't fire, or it had no electrical power at all?
Here's instruction (http://www.eilenberger.net/K75S/IgnitionSwitch/index.html) concerning Gryphon's observation. If the dash lights shut down when the power shut down, the ignition switch is a likely suspect.
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Hi, first about the Kilometers on this engine. I now have 134,000 - 76,500 = 57,500. The engine had about 110,000 on
it when I put it in. Now this engine has about 167,500 Kilometers on it.
With the flooding problem I did
"After research cleaned the coolant temp sensor wire connection
and ignition switch with Deoxit 5. "
Hope this is fixed now.
I will remove the tank and check the frame ground. When I put the engine 5 years ago I cleaned the connection
and put some dielectric grease on it.
I will put a new fuel filter in. I will also replace the spark plugs/wires.
Will also look for any electrical problems at the same time.
Thanks Jethroww
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Hi, first about the Kilometers on this engine. I now have 134,000 - 76,500 = 57,500. The engine had about 110,000 on
it when I put it in.
Thanks for the clarification. I see you were equating "bike" with "engine" and I wasn't.
Could you answer my question concerning the dash lights and stalling?
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Hi, sorry had reply back and preview lost that whole reply.
Must a mist it 😁 in 2nd attempt.
Yes everything else works. Lights stay on and I can crank
engine but no start. No sputtering missing. Just 1 second
running fine then dead. Have replaced the Hall sensor this
April with a ECE I bought last October after that episode with
the same cutting out as now. Could that have broken with
only about 800 Kilometers and 2 weeks of use?
Thanks Jethroww
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Put your ear to the left side of the tank. When you hit the start button you should hear the fuel pump whir. (It only runs when the engine is turning.)
If you don't hear the fuel pump whirring then it's most likely the fuel tank connector.
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Hi, will listen and Deoxit the connection when I take the tank off to check the ground.
Ok that explains why I only heard the pump after I let go of start button.
Thanks Jethroww
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The fuel pump connector usually fails internally. Deoxit won't hurt anything though.
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Hi, cleaned the frame ground.
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Cleaned the tank/pump connector and found the top left
connector was a bit brown looking.
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Replaced the spark plugs and wires. The plugs had 0.038 to 0.040 gap.
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Old wires.
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Picture of pump. Used a screw driver to see if I could move
the connected wires. No movement at all. Will change filter
when tank is almost empty.
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Cleaned the battery connections and ground to transmission.
Bike started and ran ok as I worked through these repairs.
To see that I didn't cause any other problems along the way.
Will have to go on a long ride hopefully this week.
Thanks Jethroww
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Will change filter when tank is almost empty.
Why wait? Use one of these (https://www.canadiantire.ca/en/pdp/certified-siphon-hose-0283044p.html) to empty the tank fuel into a fuel can temporarily any time you want to get in there.
Your fuel pump's position is hanging low in the vibration damper; it should be similar in position to the one in the photo below if its an OEM pump. Verify that it is not loose. I encountered one that was bottoming out on the floor of the tank, its filter basket was damaged and the mess was causing fuel intake restriction. View what you've got in there.
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If you suspect that it is the fuel tank connector then you can bypass the connector and run power directly to the fuel pump with some extra wire and a couple of ring terminals. (The smaller terminal is 12V, the larger is ground.) Then use some Posi-Taps to tap into the green/white (12v) and brown (ground) wires on the other side of the connector.
(https://i.imgur.com/ytUHAt7.jpg)
(https://i.imgur.com/sYbocmZ.jpg)
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Hi Laitch, I will pick 1 up this week and empty th tank.
I have only changed the filter a few years ago.
The pump I have never touched. Will pull it and
see how it looks and change the mount if possible.
frankenduck thanks for that info will try if the pump stops.
Thanks Jethroww
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Hi, changed the fuel filter another Carquest #86032 . Pulled the pump and everything
was tight. Noticed the pump filter was not seating properly on the vibration damper.
Removed the pump and installed the screen properly. Matched the 2 pump groves
with the 2 in the damper. Was on a slight angle before. The pump screen has a smash
rip on the part that sits against the pump. The damper felt a bit rubbery/soft. Is that normal?
Should it be replaced? What would be a good place to get the parts?
Euro Motoelectrics, beemerboneyard? Here is a picture of the pump as found in the bike.
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Will take it for a long ride and see if I fixed the problem. Will order parts after some
suggestions on a good quality part/suppliers.
Thanks Jethroww
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The damper felt a bit rubbery/soft. Is that normal?
Should it be replaced? What would be a good place to get the parts?
Euro Motoelectrics, beemerboneyard?
Does the yellow arrow point at sludge accumulation inside or outside that filter basket? Replace it anyway because it looks like hell. If you rub the damper with your fingers will you get black residue on them? Regardless, my inclination from this distance would be to replace both the damper and the filter with Euro Motoelectrics stock. Is the fuel tank interior relatively clean or does it have floaters and a gooey patina on part of its surface?
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Hi Laitch, almost all was on the outside. Just a bit on the inside I think it was slowly making it's way through the screen.
I don't know what it was. I ran water from a garden watering jug back through the screen and it cleaned up. I've been
driving it for 5 years now and this is the first time I have taken the pump out. The inside of the tank is spotless silver
color. Will order the parts and hopefully continue driving the bike until I get them
Thanks Jethroww
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Hi, update on my progress. Rode to work today and 5 stops. About 200
Kilometers wither no problems. Hope it is fixed. Just some pictures of
fixes.
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I also found this under the tank. Any idea what it's for?
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Laitch will order 2 sets of the parts. Trying to get a K100 going that has sat
for many years.
Thanks for all the help.
Jethroww
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Hi. Just opened my fuel filter. Hear are some pictures.
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As mentioned many times before "change the fuel filter every year".
Thanks Jethroww
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You don't need to cut a fuel filter apart to tell how clogged it is. Just pull it out and try to blow through it in the direction of the arrow. If there's resistance then it should be replaced.
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Hi, never thought of doing that. Thanks for that tip frankenduck.
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Hi, the other reason I cut open the filter was to see what was inside. It looked black. I am wondering
if that is the damper slowly breaking apart.
Just informed by Euro Motoelectrics that the damper I ordered they don't have in stock
Laitch as you recommend Euro Motoelectrics and I can't get it from them. Would
beamerboneyard be the next best place to get one?
Thanks Jethroww
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You won't know who has what until you ask them, apparently. Try tills.de here (http://https://www.tills.de/bmw-k75-67/tank/). They're reliable. MaxBMW (https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=51739&rnd=09082020) might have them; they're reliable too. If the damper isn't discoloring your fingers when you rub it, or feels like it has a firm grip on the pump, go riding. icon_cheers
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I had two damper kits sent to me from Beemer Boneyard last month.
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I had two damper kits sent to me from Beemer Boneyard last month.
Thusly (https://www.beemerboneyard.com/nsearch.html?query=fuel+pump+damper&searchsubmit=&vwcatalog=yhst-15102260216258&.autodone=https%3A%2F%2Fwww.beemerboneyard.com%2Ffuelsystem1.html).
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Hi, Euro Motoelectrics is shipping everything except the vibration damper. Would the pump filter screen
from Euro Motoelectrics fit a pump damper from the beamerboneyard or the other places that sell
the vibration damper? Have put about 400 Kilometers so far on the bike without any problems.
Thanks for all the help.
Jethroww
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It's the pump diameter and the damper diameter that must be compatible. The cylindrical filter screens fit the 52mm pumps. The pump fits into the damper then the screen fits to the bottom of the pump. So when parts are ordered, it's important to know what you've got.
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Hi Laitch, I did measure and I have the 52 mm pump. The damper that's on now just feels
soft and it seems a bit swelled up. Had to force the damper into the pump screen first .
Them the pump in. Seems to be working ok.
Thanks Jethroww
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You didn't remove the damper holder from the tank and do the assembly outside the tank?
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Laitch I did remove the damper and pump from the tank. Cleaned and reassembled it. New filter and reassembled
all back in the tank without any problems. Ran great today in this hot weather.
Jethroww
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Even a new damper is a tight fit.
Damper into the pump screen first, then slide the pump down into the damper.
WD-40 is your friend here.
Sounds like you've got it. icon_cheers
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I'll just join the TED talk going on here with these illustrations from the BMW K100/K75 Repair Manual downloadable from this site. :laughing4-giggles. Boringly, installation is the reverse of these steps.
(http://www.motobrick.com/gallery/4/1601-150622231814.png)
(http://www.motobrick.com/gallery/4/1601-150622232004.png)
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Hi, I do have the Clymer manual. It just seems the damper has swelled up a bit making it very hard to get the pump screen on . So that's why I put the pump screen on first. That's why I was thinking of getting a new damper.
Thanks Jethroww
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Hi, I do have the Clymer manual. It just seems the damper has swelled up a bit making it very hard to get the pump screen on . So that's why I put the pump screen on first. That's why I was thinking of getting a new damper.
Well, I guess aging is finally working its magic on my comprehension. First, the images aren't from Clymer; they're from BMW and have more detail. Secondly, the damper shouldn't make the pump screen "hard to get on" because you push the pump screen onto the pump after the pump has been installed into the damper.
But all this is fuel through the return line anyway, because you're back underway regardless of the convolutions in the route you took to get there. 112350
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Hi
I experienced a similar problem.
Intermittent shut down of the motorcycle.
Fortunately for me, I traced it back to the connector to the alternator.
It’s a spade connector and over time, became loose.
I tightened the connector and all is well.
Perhaps check all your electrical connections and ground points. Clean and retighten.
Throwing money and parts at your bike won’t always fix the problem.
Good luck!
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Hi just an update, been my daily driver since the repairs with no problems.
Laitch I was thinking of getting the - fit for E10 fits 52mm pump damper from
tills.de. Would that be the better choice to prevent this happening again?
I will be buying 2. I am working/resurrecting a 1989 K100RS-SE
Thanks
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I was thinking of getting the - fit for E10 fits 52mm pump damper from
tills.de. Would that be the better choice to prevent this happening again?
Jethroww, my dude, congratulations on your outcome, but botched assembly and neglect were likely the major factors in this incident and you can control them. In the tills list I'm reading, there is "no fit for E10" pump damper for a 52mm pump like the one you seem to have, only a "fit for E10" pump damper for a 43mm pump. All those dampers should be suitable for E10 if you ride your motorcycle plenty and not use it for a fuel storage dump.
By all appearances, your current pump is a 52mm therefore a 52mm damper is required, and probably a new pre-filter. Measure the K75 pump's diameter to verify and measure the K100's pump also because pumps get changed and swapped among some motos during their lifetimes and their measurements might not conform to the published specs for their model years. If a damper is firm and not "swollen" or gooey, it doesn't need to be replaced.
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Hi Laitch, I found the E10 when I clicked on the description. Here is the link.
https://www.tills.de/vibration-damper-fuel-pump-52mm-replacing-bmw-16121464628-and-bmw-16121450712-745-1077.html
Thanks Larry
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Clicking on the description—what a concept! :laughing4-giggles: Get 'em if you need 'em. Mine has its original.
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Hi, It's back. This morning going to work doing about 140 KMH. The bike just died again about 40 minutes into my commute. Three lanes over to my right got on the shoulder and coasting. Maybe about 15 seconds later still coasting the bike came back to life. Back up to 140 KMH and 20 minutes late made it to work without any problems. On the way home driving for about 1 hour. Hit a few red lights in town before the bike just died again. Tried starting it a few times and wouldn't start. Parked bike on shoulder of road and went to my appointment. Came back about an 1 hour and 20 minutes later. The bike just started right up. It did cut out about 2 minutes late but instantly came back to running with no problems. Made it home in about 20 minutes with no other problems. I thought I had found the problem as a bad/corroded fuel pump conection under the seat last time. I cleaned it a few times with Deoxit and put a small amount of dielectric grease on the connection. I now have 138,584 kilometer on the bike. Will give another good cleaning to the connector and hope that fixes it. Any other ideas to solve this problem would be appreciated.
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It's usually either a flaky ignition switch or power to the fuel pump. And even though you cleaned the ignition switch it still might be flaky
Here's what I'd do to diagnose:
Get a couple of 12V LEDs. Wire one between ground and the green wire from the ignition switch. Wire the other to ground and the green/white wire on the tank side of the connector.
Tape the LEDs to the front of the dash pad so that you can see them while riding.
If the ignition switch LED goes out when the bikes dies then you probably need a replacement ignition switch.
If the ignition switch LED stays on but the fuel pump one goes out then it's probably the fuel level sender connector.
If both stay on when the bike dies then it could be a flaky connection where the fuel pump power passes thru the fuel level sender.
(PosiTaps are useful for tapping into wires.)
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Hit a few red lights in town before the bike just died again. Tried starting it a few times and wouldn't start
Does that mean it would crank but wouldn't start, or wouldn't even crank?
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Hi, will try and get some 12volt led lights and see if that works.
The bike cranks over just won't fire/start. The lights on the dash
still work and it seems everything else is working. Just seems
like a kill switch was pushed. It doesn't miss or sputter/lug etc.
Just stops running/firing with everything else working.
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The ignition switch on my K75RT does the same thing every 4-5 years. A good cleaning as and careful reassembly fixes it. That switch is a piece of poorly designed crap. There is almost no pressure pushing the contacts together. The smallest spec of crap will break the connection.
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Hi, will clean the ignition switch again. Might try and find a stronger spring for the switch.
Thanks
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Another thing that might be worth checking/cleaning is the kill switch:
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/startkillrehab/startkillrehab.htm
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Hi, cleaned start/kill switch. The picture on the white paper is before I cleaned it.
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Have bought 2 12 volt led bulbs to attach as frankenduck suggested to see which one goes out when bike stalls.
Only problem is I can't find the PosiTaps here in Cambridge Ontario Canada. Any suggestions on were I could get
some would be appreciated.
Thanks
][/attachment]
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Here's what happened when I put the words positap canada in Google's search window and click to search.
https://motorcycleinnovations.ca/products/posi-tap-connectors-16-18-ga (https://motorcycleinnovations.ca/products/posi-tap-connectors-16-18-ga) You could also order through Amazon. I haven't found them locally in Vermont so have always bought them online.
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If you can't find the Positaps locally, you can accomplish the same thing with a couple straight pins and some alligator clip test leads.
Carefully push the pin into the wire you want to test, no need to go all the way through, just far enough to reach the conductor inside. Clamp the alligator clip test lead to it and connect to your test equipment.
When you are done pull out the pin. The hole is very small, but if you are concerned about water getting in, you can seal it with a drop of nail polish or paint.
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Hi, just thought I would mention that about 4 weeks ago my fan stopped working . Ordered a Spal and installed it. The old one was completely melted together. I do have the switch installed to turn it on. Could this heat from melting the fan contribute to this engine just stopping? Should I take the tank off and clean the 2 big switch wires? Waiting for the Posi Taps to try and see if that could be the problem. Thanks
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Could this heat from melting the fan contribute to this engine just stopping?
Unlikely. Should I take the tank off and clean the 2 big switch wires?
Is it the wires that are big or is it the switch that is big? What's the function of the switch? I'm only partially awake but that isn't stopping me from asking. :laughing4-giggles:
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Hi, if my memory serves me. They are a round clear plastic wire connection on either side of the large frame tube. I think that is the connection for the main handle bar controls. Lights/blinkers etc. Thanks
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On a neglected Brick, all electrical connectors should be inspected and cleaned. The most common causes of trouble among these waifs are poor ground connections and clogged fuel systems, including the injectors. After those, orderly testing of wiring from switches and relays can help eliminate suspects. You've had suggestions from Mighty Gryph and frankenduck so if you haven't followed them yet, you might follow through with them.
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If you can't find the Positaps locally, you can accomplish the same thing with a couple straight pins and some alligator clip test leads.
Carefully push the pin into the wire you want to test, no need to go all the way through, just far enough to reach the conductor inside. Clamp the alligator clip test lead to it and connect to your test equipment.
When you are done pull out the pin. The hole is very small, but if you are concerned about water getting in, you can seal it with a drop of nail polish or paint.
That's a good idea for a temporary tap. 112350
You could also solder a wire to the pin. Soldering flux would help a lot.
The other option without PosiTaps would be Scotchloks but I hate those because they can cut into the wire that you're tapping into.
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Hi, Removed the tank today and cleaned with Deoxit all the connectors I could find. They all looked good. Reassemble with a small bit of dielectric grease on each connector. Received my posi taps and made the connections as frankenduck suggested. The green wire from the ignition switch and the green wire from the the tank side of the tank connection. The tank had a solid green and a solid white wire no green/white combination. When I turn the ignition on to star the bike the led from the igniton is on. The tank led light only comes on when the bike is running. Hope the solid green was the correct wire. Now will have to take the bike for a good drive and see if it happens again. Thanks for all the help.
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All sounds good. The Grn/Wht wire from the main harness connects to the fuel pump power green wire of the fuel level sender so you did tap into the correct wire.
The fuel pump only gets power when the motor is turning (starting or running) so your LED behavior sounds like everything is working.
Now that you went through all of this trouble your bike will probably not fail again. :laughing1:
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Now that you went through all of this trouble your bike will probably not fail again. :laughing1:
It's the reverse of the Shrödinger's Cat: It only declares itself dead/alive when you're NOT looking at it.
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It's the reverse of the Shrödinger's Cat . . .:
Sometimes found in scientific reference as Tac Sregnidörhs.
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Hi bike just stopped running on my way to work 5:30 am. Both of the LED lights were on when the bike stopped. The tank led stayed on tor about 2 seconds after it just stopped running. Could it be the hall sensor again. I replaced it with one Euromotoelectrics. If memory serves I replaced the hall sensor last year. Going to wait about 30 min and see if it will start back up.
Thanks
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8Hi again. Tried starting and no go. Looked around and saw wet pavement under the exhaust. Pulled fuse 7 and bike started up. Put fuse back in and made it to work. Could I some how disconnect something so I could make my 1 hour drive home tonight? Thanks
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Also the bike seems to be running hotter. I put new red Toyota aluminum coolant in when I replaced the melted Bosch fan. If this helps diagnose the problem.
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If you mixed the coolant at a 60:40 or 50:50 coolant:water ratio, there should be no problem with overheating unless the thermostat is defective. Did you ever dismantle and clean the ignition switch as has already been recommended in this thread?
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hi, yes that is one of the first things I did when it was recommended. I have never changed the thermostat. Would you know the size of the o-ring ? I could see if I could get 1 at Carquest or Napa. I do have a replacement thermostat that i purchased from Napa a few weeks ago.
Thanks
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Concentrate on the matter at hand—intermittent stalling and starting failure. Don't go into the weeds. Your engine isn't overheating unless the fan is running and the temperature light is on—given that the light bulb works. Leave the thermostat alone right now.
Have you determined that the fan works?
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Hi Laitch, I replaced the fan about 3 weeks ago. The old one stopped working. Would not come with the fan button I installed a few years ago. When I got it all apart the fan brushes all melted together. Put a Spal fan as an replacement.
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Does it work as intended, i.e., when the Brick engine is idling does the fan cycle on then off in 20 minutes or so? Have you checked that out yet?
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Hi, no I haven't tried that. I have just been drive to work and back. I think I'll turn the fan on for my drive home. If I make it home I will let it idle for 20 min and see if the fan turns on. Thanks
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If the fuel pump power LED stays lit until after the bike quits then that is good. The fuel pump only gets power when the engine is turning. (starting or running)
Hall Effect Sensor:
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hes.diagnose/hes.diagnose.htm
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Hi. Will take a bottle of water with me on the drive home. If it stalls I wi put some water on the hall sensor cover and see if she will start back up. Just replaced the ha sensor last year.
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Hi I did make it home tonight. About 5 min into ride the bike stopped/started all by itself. All in about less than a second. It would just stop as it did on my way to work this morning. Left the fan running for the drive home. Turned the fan off when I got home and left the bike running. About 3 min later the fan came on automatically and then I turned the bike off. So I think the fan is working properly. I didn't take the highway home. So I didn't reach 140 Kilometers per hour speed. If that would cause anything?
Thanks
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So I didn't reach 140 Kilometers per hour speed. If that would cause anything?
That causes the braids of your beard to ripple in the draft.
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About 5 min into ride the bike stopped/started all by itself. All in about less than a second.
That sounds like a loose/flaky electrical connection SOMEWHERE.
First things I'd check - pull apart -reseat:
Ign control unit (black box up behind the steering head)
Connector for HES (under right side of tank, goes to ICU and has rubber boot around it)
L-Jetronic
Battery ground down near the shift lever
Central grounding point (lots of brown wires under center of tank bolted to the frame
If you have the tank off and want to make sure that your temp warning bulb is good:
(https://i.imgur.com/SfCnbXh.jpg)
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Hi, cleaned/Deoxit everything under tank including ECU I think it is called. Last Friday morning rode for about 1 hour with no problems. This morning about 30 min into commute just on the 401 highway bike cut out. This time seemed like it was a fuel problem. Got on the shoulder and the bike started running again. Back up to 120 and about 10 min later same thing. Shoulder of highway and bike started back up. Turned around and on my back home bike started to miss fire then run normal. Then just miss with any throttle. Seems to idle but any gas and starts missing. Like only running on 2 cylinders. Side of road waiting for CAA.
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It's time to list everything you've done to remedy this so far—what you've disconnected and cleaned, what you've disassembled and cleaned, what you've inspected and kept, what you've tested or inspected then replaced. Doing that in this post will make it easier for readers to assess what might be happening to your Brick without backtracking and missing something or suggesting something that has already been done.
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Hi. Ok will make s list tonight. Also for got to mentioning last post that both of the 2 led light stayed lit when this was happening this morning.
Thanks
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Hi this is the story.
- April 2017 bought 1988 k75s with 76,634 Kilometers. Didn't hear it running. Bought battery and after starting bike engine made a loud banging noise.
- replaced engine with I think a 1987? With about 125,000 Kilometers on it.
- ran fine no problems.
- cut out like ignition stoped working a few times over the first 4 years it was my summerdaily driver.
- September 2021 132,223 Kilometerson the bike odometer and the bike just stopped running the started right back up. About 15 minutes later just stopped running. Seemed fuel pump stopped running. Didn't hear pump running when I tried to start bike. On shoulder of road looked bike over. Checked fuses, wires I could see battery all see okay. About 45 min later tried starting bike wouldn't run but I heard the pump running after I let go of the starter button. 2 more tries and bike started running. Drove for about another 35 min home without any problems. After some research I thought it could be the hall effect sensor. Started and let the bike idle for about 30 minutes a few days later. About a week later started the bike up and let it idle again. About 20 minutes later the bike just stopped running. Tried starting it again with no luck. Tried starting again a few times different days and it wouldn't run.
- October 2021 bought Hall effect sensor from Euro Motoelectrics.
- 132,500 April 2022 installed the Hall effect sensor
- 135,345 bike seemed it wasn't getting enough gas. Checked tank and seen fuel pump damper was big with soft/ sticky rubber feeling.
- 133,565 June 11 2022 new spark plugs/wires, cleaned ignition switch and coolant temperature connector with Deoxit and small amount of dielectric grease put on connectors.
- 135,993 July 19 2022 new fuel pump damper/screen & new fuel filter
- 137,718 Aug 13 2022 new Spal rad fan( old 1 had melted together brushes) ,Toyota red coolant, cleaned wire connections under seat with Deoxit and small amount of dielectric grease added
- 138,645 Aug 21 2022 cleaned start/kill switch with Deoxit 5 and small amount of dielectric grease added.
- 138,797 Aug 29 2022 just stopped running about 1 hour into commute to work. Would not start . Pushed bike for a while. Tried startup again and wouldn't start. This was about a 1/2 hour later. When it got light outside I saw a puddle under the bike. Though it was gas. So I pulled the #7 fuse and the bike started up. Made it to work. Turned the fan on for the drive home. About 5 minutes into drive home the bike died/started right back up in less than a second as before. Made it home 1 hour drive without any problems. I turned the fan off but let the bike idle to see if the fan was working. About 3 minutes later the started automatically without the coolant light coming on. Then I turned the bike off. (Should have let it run to see if it automatically turned off)
- Aug 31 2022 removed tank. Cleaned ECU with Deoxit 5 & put a small amount of dielectric grease on. Cleaned all the connectors again with Deoxit 5 and added small amount of dielectric grease on pins. Added led diode light to fan positive to see when fan turns on/off. Cleaned battery ground again.
- Sept 02 2022 drove bike for about 55 minutes without any problems.
- 138,969 Sept 07 2022 about 35 minutes into commute just got onto highway 401 and bike died but this time like it was running out of gas. Got onto shoulder and tried giving it more gas and then it started running ok. Back onto highway. About 15 minutes/20 Kilometers later bike seems as it is running out of gas again. Shoulder and the bike starts back up. Turned around and took side roads back home. About 30 minutes later bike started to miss fire. About 15 seconds later started running fine. About 1 minute later started miss firing again. Seemed like it was a different cylinder each miss fire. The bike would idle but once you turned the throttle it would bog out/start to miss fire.
Called CAA and bike is in the garage now.
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Reading your tale of woe I can't help thinking that except for the misfire, you bike is acting exactly like my K75RT when it wants the ignition switch serviced/cleaned.
At this stage of the game, my first reaction would be to eliminate the ignition switch. I would get a good toggle switch and wire it in to replace the ignition switch to eliminate that as a possible source of your problems. I would hide it under the seat where locking the seat could prevent tampering when the bike is unattended. Beyond that I have no other suggestions.
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Hi, what did you do to fix the switch problem? I have clean it once as was recommended. I do have a extra switch. Thanks for the help The Mighty Cryphon
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If the ignition switch or kill switch were faulty the dash lights wouldn't work, I think your dash lights are working.
Fuel or spark? Spark plugs wet or dry? I think they'll be wet, since sometimes you had fuel dripping out the headers.
Maybe move the test lights to before the coils, or easier a timing gun to check for power to the spark plugs while cranking, when in cranking but no start mode. Or just check if there is spark at the spark plugs.
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What is the make and model number of the spark plugs you are using and the plug wires you are using? Do the plugs have screw shank terminals or terminal nuts?
You haven't listed checking the Z-tube connection from crankcase to airbox for leaks, checking the throttle body connections to the airbox for leaks, checking the rubber caps on the throttle bodies for cracks. If the engine will idle, these parts are checked for leaks by spraying a stream of propane around them and listening for a change in the idle; a change would indicate a leak in the seal and the part probably should be replaced. A visual inspection can find obvious cracks in the rubber.
Faulty coil function could be part of this, as daveson indicates. Consult the troubleshooting guide for instructions and resistance values. Link to the guide is at the bottom of the first post here (http://www.motobrick.com/index.php?topic=11033.msg95796#msg95796).
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I just take it apart, polish the contacts with 1000 grit paper, and carefully put it back together. The last time I had to do it, it really wasn't that bad inside as it had only been 4-5 years since the last time I cleaned it. As you might have noticed, the contacts in the switch don't seem to have a lot of contact area or pressure to hold them together.
In my opinion, the factory switch isn't a very good design, and after 30+ years is probably not going to be very reliable going into the future. Also, it's location at the steering head exposes it to vibration from the engine and front wheel which also can't be good for it. As I suggested, if you could come up with a way to replace the factory switch with a good toggle switch concealed under the seat it would go a long way to either positively identify the problem and/or correct it.
You could also try replacing the original switch with your replacement.
How strong are the vibrations at the handlebars? You might want to try loosening the screws that hold the switch pad to isolate it from frame shocks and vibration, maybe even detach it completely and let it temporarily rest on some foam to absorb shock.
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Jethroww, I have experienced similar symptoms twice. One time the cause was a poor connection in the kill switch. The other time the problem was a poor connection in the ignition switch. This is a trap for young players, as the ignition switch contains TWO switches. Thus if only one of them fails, then when the switch is turned on SOME THINGS WILL WORK and some will not. This caught me out, and yes, I do know what a Hall sensor looks like. In fact I built a new one.
My advice is to check these two (or if you like, three) switches.
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Only problem is I can't find the PosiTaps here in Cambridge Ontario Canada. Any suggestions on were I could get
some would be appreciated.
. Try Cruchfield: https://www.crutchfield.ca/S-poMuwoh6Ddb/shopsearch/posi-products.html
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I always get my Posi-Taps from Ebay.
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If all you are going to do is check the voltage in a wire you don't need the Posi-Taps. Just sick a pin in the wire and attach an alligator clip to it. A pin will make a smaller hole in the insulation than the Posi-Tap.
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Hi Jethroww,
Great and interesting post. It's nice you've been trying all the ideas that this forum have suggested. I did notice that you pulled/replaced fuses and were able to get it running after a while. My K100RS had a few weird electrical gremlins that were all related to the fuse box. In my case, the fuse receptacles were dirty which was causing my issues. Once I cleaned them I had no more issues. It makes sense that a poor electrical connection there would cause more heat, and a worse connection, and then the problems show themselves until the fuse connections cool down. Not sure if you've done this, but I would clean the heck out of those receptacles, as well as the fuses themselves. The spring tension of my fuse holders seems very weak, but keeping them clean seems to work well enough. Best of luck!
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Update
Latest changes
139,006 July 14 2023. Changed temp sensor
As suggested by rbm and other members changed the starter brushes
Here are pics of old and new
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141,749 Aug 06 2023 back to daily driver
Thanks everyone for all the help and hope this might help others.