MOTOBRICK.COM
MOTOBRICK.COM => Welcome To Motobrick.Com => Topic started by: GREGT on February 17, 2025, 12:50:30 AM
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So I finally bought a Brick, I've wanted one for many years and I plan to set it up for long range cruising. This one's a K75 from 88 and has the Hannigan Fairing on it with 31 K on the odometer. The bike has no records so I'm doing the grease stuff, oil, coolant and brake fluid. I'm having a starting problem now with it, but I'm pretty sure it's the ignition switch. When the weather is a little better I will post a few pics of this beautiful machine.
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Welcome, GREGT! Which model is your K75?
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By all means get some pics up. Good luck chasing down those electrical gremlins, lots of info if you search here.
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Clean K75/K100 Ignition Switch:
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/ignition2vclean/ignition2vclean.htm
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Welcome, and enjoy the rehab process with your brick. Standard rubber pieces should be checked and/or replaced, especially the pesky "Z" pipe near the fuel regulator. There's many, good sources for parts under "vendors " on this site. Cheers
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I believe the model is a K75C per the PO
Not positive the Ignition switch is the problem, but here's what happens. Turn key on and sometimes the neutral display brightness is brighter and most of the time dimmer. By cycling the key on and off eventually is gets brighter and the bike starts right up, but when it's dimmer the bike just wont start it does turn over with less starting power. I believe it could also be the neutral safety switch or even the starting relay, but that's whats happening.
The PO, changed the starter and installed a new battery as well.
The reason I'm leaning towards the ignition switch is that sometimes just slightly moving the key without turning it on and off causes the neutral light to get brighter and it will start. I should have it sorted out though within a couple of days. I will say that I'm very excited to finally have one of these and know it will provide many years of enjoyment!
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It's worthwhile to clean the grounds under the tank and on the transmission. After sitting a long time, corrosion can bugger up electrics, stirring up the gremlins.
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I believe the model is a K75C per the PO
The C is the only model that came with a rear drum brake; the rest have a rear disc brake. I believe your diagnosis of a faulty ignition switch is likely to be correct. Please keep us in the loop.
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so it is a C then as it has the rear drum brake. I will also go thru all the grounds and connections as I want this to be very reliable and I know it can be. Plan on upgrading the altenator to 50 Amps and pulling a trailer too. Will be a very cool looking retro set up when it's done.
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Early K75 standards had a rear drum. That may have just been in Europe though. Here's a BMW pic of an early K75 standard with a rear drum:
(http://bmbikes.bmw-club.org.uk/photos/specphotos/k75.jpg)
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Don't forget the K75t, a "C" modded by BMW USA with shield, seat, fairing, baggage, touring bars, lights, but still a drum brake.
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Welcome! I had a K75RT that I rode through 42 of the 48 continental states putting on 45,000 miles. The K75 is a fantastic touring bike.
Clean the ignition switch. The design is not all that good and is sensitive to dirt and oxidation. I have had issues with two of them. Your symptoms sound similar to what I have experienced. Do the disassembly and service with the switch in a box or pan. There are some very small parts that are very easy to lose making the switch useless. I had to learn the hard way, spending several hours on the garage floor on my hands and knees with a flashlight.
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Yeah, Thank you for the very good advice. I've been there looking around on the floor too! I'm hoping to have everything done before the end of April so I still have some time. Hopefully, the Alternator guy gets back with me so I can get that swapped out. In the mean time, I will pull the belly pan and remove and clean the oil pan out, check the pick up screen, and reassemble that. Get the switch cleaned for the ignition. I ordered a trailer hitch and that should arrive by the end of the Month. Would like to upgrade the headlamp and add some fog lights, gators for the forks, and then figure out the trailer lighting.
The trailer I bought is all LED so I will need to tie all of that in with the bike. Hopefully someone makes an adaptor to drive the LED lights. I also plan to have a Lithium Battery in the trailer so I will probably use some type of Anderson plug for that. The good news for me is I like doing research and fun projects like this!
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Early K75 standards had a rear drum. That may have just been in Europe though. Here's a BMW pic of an early K75 standard with a rear drum:
(http://bmbikes.bmw-club.org.uk/photos/specphotos/k75.jpg)
Where's the pic?
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Going to be a while before pics. The bike's is in my warehouse and needs reassembly and the I have to figure out how to even send pics on this site. Read the instructions kinda looks like instructions from Mission Impossible, may need help from my Son for that. Will take the bike and trailer outside for pics, but it's not exactly nice weather here.
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Where's the pic?
Works for me.
Try this link:
http://bmbikes.bmw-club.org.uk/photos/specphotos/k75.jpg
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So my first problem of the bike not starting due to the dim neutral light is now solved.
Thank you Frakenduck for the link showing step by step instructions on how to disassemble the ignition switch.
One note is that reassembly, although not shown, is done by putting the brass pieces into the white plastic insert.
So I carefully took it apart and the inside was actually pretty much clean. I took a pencil eraser to all the contacts and then put it back together. I then realized I forgot to lube the contacts so I took it apart again. I sprayed a light amount of silicone lube inside and put it back together again.
As a safety precaution, I checked it with my meter before trying it on the actual bike. My confidence of this solving the problem was actually quite low as the switch was so clean to begin with. Once installed though the bike now starts everytime!
Thank all of you for your help and support!
Now off to the next step remove and clean oil pan and check pick up tube.