Post by: gkanai on September 04, 2021, 04:43:47 PM
I just picked up a K75C at auction for a very reasonable price. It apparently has less than 10,000 kms on the odometer, which is hard to believe. The previous owner said it ran about two years ago but it's no longer registered for the roads (in Japan.)
I'm going to rehabilitate it and put it back on the road, maybe with a new coat of paint. I have some mechanical ability, but I will also rely on a specialist vintage BMW mechanic in Tokyo (Flat BMW) who is near me. I have a ton of questions but will take time to go through the information on the forum. I'm very much open to ideas/advice.
One of my main concerns is about suspension. I'm a large rider and the OEM stuff is old, so I'm planning new springs up front, and a whole new rear shock. Any guidance on that area would be welcome.
Let me share photos in the next post.
Post by: gkanai on September 04, 2021, 04:46:23 PM
(http://www.motobrick.com/gallery/3/7480-040921163529-38251805.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163529-38252379.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163528-3823978.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163527-38201427.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163527-38211774.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163527-38211655.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163528-38232030.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163526-38172486.jpeg)
(http://www.motobrick.com/gallery/3/7480-040921163526-3817311.jpeg)
Post by: AtLarge on September 04, 2021, 04:58:36 PM
Post by: gkanai on September 04, 2021, 05:06:54 PM
I'm looking for luggage. Does K1100LT luggage fit this bike? (Is all K-Bike luggage similar?)
Post by: Laitch on September 04, 2021, 05:41:09 PM
I'm looking for luggage. Does K1100LT luggage fit this bike?Yes. The racks are the same for all models.
Post by: gkanai on September 04, 2021, 05:49:36 PM
Yes. The racks are the same for all models.
Great- thank you. I'll start looking for used luggage and mounting rails.
Post by: natalena on September 04, 2021, 06:32:26 PM
Likewise, I have a K75, and have been happy with a YSS adjustable shock on the rear, and progressive springs in front with 10wt oil. We ride 2 up with luggage, so it works well for a load. Enjoy getting it back on the road!
Post by: gkanai on September 04, 2021, 07:05:57 PM
Welcome, and great looking brick. Is it a 1987?
Thanks! When I saw the mileage and the price, I had to grab it.
I do not know the year yet- the previous owner is still working to get it shipped to me.
Thanks for your thoughts on the YSS suspension. I'm looking at YSS but also IKON and the Progressive shock as well.
Post by: gkanai on September 04, 2021, 09:01:20 PM
BATTLAX BT46 100/90-18 M/C 56V TL
ContiRoadAttack 3 100/90 R18 M/C 56V
DUNLOP ARROWMAX GT601 100/90-18 M/C 56H
REAR
BRIDGESTONE BATTLAX BT-46 TOURING 120/90-18M/C 65V T/L
ContiRoadAttack 3 CR 130/80 R18 M/C 66V TL C
ContiClassicAttack 120/90 R18 M/C 65V TL
DUNLOP ARROWMAX GT601 120/90-18 65V
Post by: The Mighty Gryphon on September 04, 2021, 10:53:30 PM
For the front end, I would suggest investigating Race Tech cartridge emulators and single rate springs.
I put them in my K75RT and the improvement in handling and ride was noticeable. Brake dive was greatly reduced while smoothing out the ride harshness over rough pavement. I run Automatic Transmission Fluid(ATF) in my forks.
Post by: gkanai on September 04, 2021, 11:15:16 PM
+1 on the YSS rear shock. For the price, it is a very good deal. I am very happy with mine.
For the front end, I would suggest investigating Race Tech cartridge emulators and single rate springs.
Thank you! Did you get the YSS with the external reservoir or not?
I've run Race Tech springs Gold Valves before- I'll do the same this time.
Post by: The Mighty Gryphon on September 05, 2021, 07:28:46 AM
Post by: gkanai on September 05, 2021, 12:02:04 PM
Post by: volador on September 05, 2021, 01:24:10 PM
On your moto, do to the 'rear drum brake' your upgrade would require newer type final drive and rear disc brake assembly.
If you do upgrade need to make sure the newer Rear 'Tri-spoke' rim is of the 'TYP B'
K75 Rear Tri-spoke rim markings should read 36.31-2 310 188 MTH2 3.00x17E TYP 'B' which is not the rim part# but must be a manufacture# or such
I read rear Tri-spoke rims of the 'TYP A' and 'TYP B' have different off-set. I never measured to verify.
Probably because of paralever vs. monolever final drives rear wheel rim installs.
Post by: gkanai on September 06, 2021, 02:04:06 AM
Post by: volador on September 06, 2021, 02:51:35 AM
@volador, thank you. That's a lot to think about. I may stick with the 18" wheels and see how that goes.
I agree, tough finding the parts. Use what you got, its very nice looking moto, good tire choices.
If that is the correct kilometers you are lucky dude.
Apply 303 Aerospace Protectant, Meguiars M40, or ArmorAll to revive all the plastic, vinyl parts
Check condition of the inside of fuel tank. Lowest portions are prone to corrosion when moto is left sitting for some time.
Rubber fuel pump damper will disintegrate over time left sitting in petrol.
(http://i397.photobucket.com/albums/pp59/mblytle/k75%20x2/20170704_161956.jpg)
Some links for your K journey Good Luck
Just bought a 2V (http://www.motobrick.com/index.php/topic,370.0.html)
Just bought a 4V (http://www.motobrick.com/index.php/topic,465.msg960.html#msg960)
K75s midlife refresh (http://www.motobrick.com/index.php?topic=7810.0)
Check parts compatibility with BMW MAX Microfiche, BOBS BMW, REAL OEM
https://shop.maxbmw.com/fiche/PartsFiche.aspx
https://shop.maxbmw.com/fiche/PartsSearch.aspx
https://parts.maxbmw.com/BMW___BmwMotorradK.html
https://www.bobsbmw.com/store/microfiche/BrowseSeries.aspx
https://www.realoem.com/bmw/select.do?kind=M&arch=1
https://www.ascycles.com/BMW-Motorcycle-Parts-Fiche
Cross reference parts like Bosch pn#'s, etc.... http://partsplusecat.com/
No spaces in the part number
Parts Vendors
https://www.beemerboneyard.com/
https://www.capitalcycle.com/
https://www.euromotoelectrics.com/
https://www.tills.de/
Headlight relay stuff if you chose to add one
https://www.motobrick.com/index.php?topic=268.0
http://www.motobrick.com/index.php/topic,4962.msg30932.html
http://culayer.com/product/matchbox-headlight-relay/
http://easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html Eastern Beaver site is a great reference for electrical connectors,plugs, etc...
http://www.k100-forum.com/
http://www.kforum-tech.com/Tech-page.html
http://www.kforum-tech.com/electrical/EFI/bike-wont-start-EN.htm
http://www.kforum-tech.com/Downloads/electrical/diagrams/interactive_diagrams.htm
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/k100tshoot/K100.Troubleshoot.Start.2018.pdf
http://kbikeparts.com/index.htm
http://www.kbikeparts.com/classickbikes.com/ckb.tech/ckb.new2k.htm
http://www.kbikeparts.com/classickbikes.com/ckb.tech/ckb.tech.toc.htm
http://www.eilenberger.net/K75S/IgnitionSwitch/
http://www.verrill.com/moto/moto.shtml
this site has a lot of good info and breakdown pictures in the tech and tech resources sections for K1100 alot of the parts are on K75 & K100
http://www.k11og.org/forum/index.php?sid=2df953dde5715fd9001fbe69edec5ad0
https://ibmwr.org/index.php/k-bike-tech-articles/
This site has all kinds of technical specifications on all the BMW models http://www.bmbikes.co.uk/mechanicalpages/kseriesmechanical.htm
http://largiader.com
http://bmwk10075abs1fix.web.fc2.com/index.html Toshi ABS site
Hosa D5S-6 CAIG DeoxIT 5% Spray Contact Cleaner, 5 oz. (https://www.amazon.com/gp/product/B00006LVEU/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1)
CAIG Laboratories D100L-25C Contact Cleaner Needle Dispenser (https://www.amazon.com/gp/product/B0000YH6F8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
Oil/Water Pump
pre-1986-87? original design old style impeller 11411461177
Superseded by 11412325850 design change the shaft with gear Z=32 teeth, shaft- 11411461183
Superseded by 11417676366 same shaft with gear Z=32 teeth
latest design 11517676371 design change shaft with gear Z=19 teeth, shaft- 11411461793
3-Bond 1184 Service Bulletin (http://www.motobrick.com/index.php?topic=13176.0)
Slip-ring seal for water pump Service Bulletin (http://www.motobrick.com/index.php?topic=4994.0)
Oil Water Pump Seals K-models SB 11 039 89 2352 (http://www.motobrick.com/index.php?topic=14497.msg129643#msg129643)
https://www.euromotoelectrics.com/product-p/pumpkit870.htm (https://www.euromotoelectrics.com/product-p/pumpkit870.htm)
https://www.euromotoelectrics.com/product-p/pumpkittool628.htm (https://www.euromotoelectrics.com/product-p/pumpkittool628.htm)
Post by: gkanai on September 07, 2021, 07:56:48 AM
I now know my bike is a 1986 model.
The YSS dealer in my country says that the spring that they normally sell on the shock for the K75 is ID46 45-60N/mm L-220mm.
That spring is way too weak for my weight. YSS thinks that I would need a 100 N/mm spring but that the largest they have is 80N/mm.
I may have to look beyond YSS.
Post by: gkanai on September 07, 2021, 06:17:34 PM
Welcome, and great looking brick. Is it a 1987?
Likewise, I have a K75, and have been happy with a YSS adjustable shock on the rear, and progressive springs in front with 10wt oil. We ride 2 up with luggage, so it works well for a load. Enjoy getting it back on the road!
It's a 1986, I now know.
Regarding your YSS shock, did you replace the OE spring with a heavier spring to account for your passenger? Do you know the spring rate of the spring? Thank you in advance.
Post by: gkanai on September 23, 2021, 01:58:03 AM
(http://www.motobrick.com/gallery/3/7480-230921014943-38581519.jpeg)
(http://www.motobrick.com/gallery/3/7480-230921014942-38562160.jpeg)
(http://www.motobrick.com/gallery/3/7480-230921014942-38562450.jpeg)
(http://www.motobrick.com/gallery/3/7480-230921014940-3850663.jpeg)
(http://www.motobrick.com/gallery/3/7480-230921014940-38501657.jpeg)
Post by: stokester on September 23, 2021, 06:35:08 AM
I don't see any oil in the sight glass! :johnny
Post by: Laitch on September 23, 2021, 09:32:21 AM
Apply heat and then Liquid Wrench or its equivalent to all stubborn, rusted fasteners; otherwise, it should clean up fairly easily with a case of Scotchbrite pads and rattle-can paint to become the glorious icon of moto transport it was meant to be. :laughing4-giggles: Although the parts fiches show that seat strap, the one on yours is the first one I've seen in a member's photo. 112350
Post by: gkanai on September 23, 2021, 10:29:46 AM
I don't see any oil in the sight glass! :johnny
Thank you for the feedback on tires. Metzeler doesn't sell any tires that fit the K75 in Japan apparently.
The bike only has the side stand, so that's why there's no oil in the sight glass. I'm going to look for a used centerstand and the parts to make that work.
Post by: gkanai on September 23, 2021, 10:31:33 AM
It is certainly photogenic but slightly disappointing in person. I'm like that, too.
LOL! Yeah, me too. Thank you for the advice on the Scotchbrite- will buy a box and will look for a gas heat source
Post by: The Mighty Gryphon on September 23, 2021, 11:56:05 AM
Follow the cleaning with a self etching primer and then your paint. I find that a semi-gloss engine enamel works well.
Post by: gkanai on September 23, 2021, 12:41:40 PM
The engine corrosion can be cleaned up with an aluminum cleaner. Aluminum Jelly is a product that can be used. I also use aluminum brightener that I get at the auto parts store.
Follow the cleaning with a self etching primer and then your paint. I find that a semi-gloss engine enamel works well.
Thank you! I'll look for similar products here in Japan.
Regarding finding a used centerstand- are all of the K-bike centerstands the same? Can I get a used K100 centerstand and use that on my K75?
Post by: gkanai on September 26, 2021, 07:10:35 AM
There are a few different lengths of choke cable for the K75- how do we know which one to get? Take off what I have and measure?
Post by: gkanai on September 26, 2021, 07:16:34 AM
(http://www.motobrick.com/gallery/3/7480-260921071429-38621787.jpeg)
(http://www.motobrick.com/gallery/3/7480-260921071427-38611553.jpeg)
(http://www.motobrick.com/gallery/3/7480-260921071425-38592262.jpeg)
Post by: Laitch on September 26, 2021, 10:08:07 AM
Post by: gkanai on September 26, 2021, 10:28:18 AM
A few prolonged soaks then rinses with white vinegar should help clean up the tank a little more.
Thank you. I do have some white vinegar to clean up the tank.
Will replace everything I can inside the tank.
Post by: gkanai on September 26, 2021, 11:28:02 PM
Should I be replacing my fuel injectors or can I have my OEM ones refurbished somehow?
(http://www.motobrick.com/gallery/3/7480-260921232653-38681314.jpeg)
Post by: frankenduck on September 27, 2021, 12:48:01 AM
Look around in Japan. The prices for FI service vary quite a bit.
It doesn't look like the fuel rail is still available from BMW (13531460607) so sand and repaint is the way to go unless you can find a good one on Ebay for a reasonable price. Getting it media blasted might be easier than sanding.
Post by: The Mighty Gryphon on September 27, 2021, 07:37:47 AM
Throw it into a pan of white vinegar for a couple days, then go over the outside surfaces with a wire brush and blow out the interior with compressed air, follow up with a rust converter primer and paint with a semi gloss engine enamel.
Post by: gkanai on September 27, 2021, 08:31:19 PM
You can get the FIs refurb'd. That's what I always do.
Look around in Japan. The prices for FI service vary quite a bit.
Gotcha- thank you.
Post by: gkanai on September 27, 2021, 08:32:02 PM
The only critical part of the fuel rail is where the injector o-rings seal against fuel leakage. As long as that sealing surface is good, the rail can be salvaged.
Understood- will refurbish. Thank you!
Post by: Gabriel70 on October 04, 2021, 08:05:48 PM
Just a few ideas.
-avoid painting the engine cases. I don’t think they were ever painted. I cleaned the final drive, gearbox and engine cases with a nylon brush and wd40. The front of the engine requires a more gentle approach. Please don’t use a wire brush or nylon brush on the front engine cover.
They look great, and no signs of deterioration eight years later.
-consumables such as filters, cables etc are available from Motobins and BMW Motorworks.
-buy a can of electrical contact cleaner and clean ALL connectors including the earth point under the fuel tank.
-perhaps replace the air inlet cover. It’s cheap and makes the bike look nice.
-keep it simple. Once you start messing with paints, it can turn into a mess. I have yet to see a painted engine case which I would consider looks amazingly good. Try wd40 and a nylon brush on the end of a drill and you might be pleasantly surprised by how good it looks.
-use clean rags and cotton tips/buds.
Good luck.
B6F9BEAB-F19F-46ED-AB4A-E7B6CD7DEEA0.png (26.71 kB . 432x576 - viewed 431 times)Post by: gkanai on October 05, 2021, 04:26:55 AM
Hi.
Just a few ideas.
Thank you so much for the good advice! I'm ordering nylon brushes now and will go to work.
Agreed on the contact cleaner- I'm going to have some work done by a local vintage BMW shop as well.
Post by: Gabriel70 on October 05, 2021, 07:32:03 PM
Hi
Try the nylon brush, attach it to any drill, start at a slow speed until you get a feel for the brush. Apply a small amount of wd40 and use a clean rag to wipe the cases as you go.
I’m not certain how effective this technique will be for your cases"
I used the nylon brush on the final drive, the drive shaft cover and the engine side covers. The front engine covers (which covers the timing chain) I found scratches easily.
A toothbrush and wd40 is also useful for cleaning the tight spots.
Try and avoid metal brushes and chemicals.
Good luck
Post by: Gabriel70 on October 05, 2021, 07:48:16 PM
Hi
I forgot to mention, all of my components were removed from the bike when I cleaned them.
Makes the job much easier.
I have attached a few photos of my k100 which has been kept in a shed for the last two years and is covered in dust.
The metal spacers on the footrests were purchased from BMW and rusted within weeks?
The wheels are not great.
I will be fixing a few issues within the next few months.
Post by: gkanai on October 16, 2021, 10:23:29 PM
The YSS standard spring (ID46 45-60N/mm) is rated for a 45-90 kg rider I am told. I'm heavier than that (110 kgs) and YSS sells a 80 N/mm spring. Has anyone else upgraded the YSS spring to the heavier rated spring?
Post by: Gabriel70 on October 17, 2021, 09:48:38 AM
Hi
A shock absorber is one of the most expensive parts on a motorcycle.
Wilbers is an expensive brand. YSS is a reasonable option.
How confident are you working on motorcycles.
Old motorcycles can have many issues and it can be expensive paying someone else to do the work.
I have a few ideas, based on my 20 years of ownership experience with a 1984 BMW K100 and a 1992 BMW K75s.
-familiarise yourself with the bike. Download the owners manual and the official BMW service manual. They can be downloaded for free.
-clean all the electrical connectors, especially the connectors under the petrol tank. Use a contact cleaner with an extended nozzle. Spray it into the open end of the connector and make certain you have a rag on the other end of the connector to catch the residue. It is not difficult to remove the petrol tank and it’s easy to disconnect all of the connectors.
-remove all of the fairings. It’s not difficult, especially your bike. It will give you easier access to your bike’s components.
-remove the rear wheel and the final drive. Once you’ve done that, check the driveshaft, in particular the splines.
The splines can be expensive to replace.
- eventually replace all fluids and filters.
-Please check that all the systems, that is, brakes, lights, fuel injection, engine, switches etc are all operational.
-a new shock absorber, which can be expensive should be one of the last purchases. No point purchasing a shock absorber if the rest of your bike is not running.
-Motobins and Motorworks BMW in the UK are a good source of cheap parts. It also depends on the currency exchange rate and postage costs.
-the official BMW dealership is where you will find the hard to get parts, especially the fasterners.
Good luck.
Post by: The Mighty Gryphon on October 17, 2021, 11:02:33 AM
My personal opinion is that expensive options like a new Wilburs or Ohlins shock for our old bikes isn't terribly financially responsible. I have had K bikes with OEM, Works Performance, Fox Twin Clicks, and YSS. Specifically, I had two 16valve K100's, one with a Fox, and one with a YSS. Both handled and rode the same once I got the preload and damping dialed in on the YSS.
As far as the YSS spring rate, give the YSS guys the information they ask for on how much you will be loading the bike and how you ride and go with what ever they recommend. I know they got me a good spring, and I haven't heard of anyone else having a problem with their setups.
Finally, if you do go with the YSS, set it up with the absolute minimum preload to get as much static sag as possible. My shock has the adjustable spring seat at the point where it touches the spring without putting any appreciable pressure on it. I found the damping works best at the lower end of it's adjustment range. I think mine is set about 1/4 to 1/3 of the way from minimum damping. These settings should give you a good ride with minimum harshness and good handling in corners.
Post by: gkanai on October 17, 2021, 12:16:45 PM
Hi
A shock absorber is one of the most expensive parts on a motorcycle.
Wilbers is an expensive brand. YSS is a reasonable option.
How confident are you working on motorcycles.
Old motorcycles can have many issues and it can be expensive paying someone else to do the work.
Good luck.
Gabriel, thank you for your valuable advice. I am doing some of the work myself and having a local vintage BMW shop do some of the work as well.
Post by: gkanai on October 17, 2021, 12:23:54 PM
Finally, if you do go with the YSS, set it up with the absolute minimum preload to get as much static sag as possible.
Thank you for the guidance on the sag- that is something I did not know.
After reading so many good experiences owners have with the YSS- I agree the Wilbers doesn't make sense.