I live in the Denver, CO metropolitan area. I’m active with the Airheads Beemer Club in Colorado. I’m a nerd interested in astronomy, astrophysics, biology, metaphysics, mathematics, psychology, education and learning. I enjoy restoring, rebuilding and working on BMW airheads, completing my fourth restore/rebuild over the past 12 years in 2020. After I retired from the corporate world, I took a part time job at a small independent vintage British motorcycle shop (BSA, Norton, Triumph). Thanks for visiting …
For you it is mountain passes, for me it is visiting Peet’s stores, I am @ 185 out of 194, have a bead on 3 more later in the month when I’m in Seattle. Unlike your hobby where new mountain passes take millions of years to develop, new Peet’s seem to pop up one or two per quarter, keeping the goal going. Cool site, Douglas Pass is way out there!
Ah, the things you find on the internet. Good to catch up with an old friend, and that you are still beating your kidneys senseless on a BMW. I have fond memories of rainy afternoons in San Antonio doing the EEAP for Fort Sam Houston with Karl Scheuch. We were passing the time pitching pennies in the bathroom of the motel room, smug in the knowledge that Larry Bickel was paying for everything, including the pennies. I still have that original TRS-80 microcomputer stashed somewhere in the garage. It has a 4 digit serial number.
hello mate and well done on the postings. quick question (i’m doing a sidecar project with a /6): what year and make did your rear snowflake come off of? i ask as i’m having troubles finding which one to get for my conversion. thanks.
I believe the front was for the /7 series when this was first available. The rear I got on eBay and it’s likley a /7 model year rim as well. You can check out the various model year/parts using Max BMW parts fiche. It’s very helpful when sorting through used parts to ensure the work on your project.
Best with the restoration and side hack project.
Brook – I have a 71 r75/5 and was cleaning some of the same parts as you did (using your outlined technique). I wanted to know what parts I can safely take off the bike (I am not a mechanic by any means). for example, can I remove the front engine cover or I think you call it a timing cover to clean it. Meaning is it as simple as removing the three bolts with the cover not being attached to any mechanical or keeping oil in the engine. same with cleaning the oil pan (which I would reckon is keeping oil in the engine) – so that one I would think I don’t want to unbolt.
Thanks for stopping by and reading some of the material I have posted.
Your question is a good one: How do you know if something you want to do will create an unexpected complication?
I could tell you what to do or I could point you to resources that you can use to learn more: said differently, I can give you fish, or teach you how to fish 🙂
Let’s try a bit of both.
If you aren’t a member of the BMW Motorcycle Owners Association (BMW MOA) please join and also access their web-site, http://www.bmwmoa.org. The forums provide “how to fish” lessons no matter what your skills are. And, any questions you post are almost immediately answered. As you read other questions, you get an understanding of how the machines work, how to work on them, and you can judge what is within and what is beyond your current tools, skills and inclination. I learn something from others postings all the time.
Now, to the specific questions:
1. To remove the timing cover safely, first remove the battery ground cable from the bolt on the left side of the transmission so all power to the bike is cut off. This protects any of the electric components under the timing cover from accidentally being short-circuited (grounded) should the timing cover touch any electric connections. In particular, at the top of the timing cover, the diode board has contacts on top that will short-circuit if they touch the cover and that’s kind of a bummer, and costly. Then, remove the three “allen head” screws and pull the cover. When you put the cover back on, align the cutout on the inside of the casting on left inside (as you face the front of the bike) of the cover with the rubber gasket on wire connecting to the points. Then align the right edge of the cover onto the rubber gasket holding the tachometer cable on the right. Look at my write-up “11 BMW R75/5 Replace Camshaft Seal” [http://brook.reams.me/bmw-motorcyle-rebuilds/1973-bmw-r755-rebuild-project/11-bmw-r755-replacing-cam-shaft-seal/] to see what you will find under the timing cover.
2. Replacing the pan gasket is covered in the write-up “11 BMW R75/5 Replace Oil Pan Gasket, Clean Oil Pickup” [http://brook.reams.me/bmw-motorcyle-rebuilds/1973-bmw-r755-rebuild-project/11-bmw-r755-replacing-pan-gasket-clean-oil-pickup/]. A time to do this can be when you do an oil change, so you don’t waste good oil. Then you can clean the oil pan, replace the oil pan gasket and fill the engine with fresh oil
So, let me encourage you to mix learning with doing. Post questions to BMW MOA and read what’s there and then go do the job. If you get stuck, there’s plenty of advice. You will acquire skills, confidence, knowledge and of course, some more tools as you go. 🙂
Brook – thanks for getting back to me so quickly. Thanks for your tip on resources – I will definitely check it out. I have spent a lot of time on the vintage BMW forum site – that’s where I found your posts as well. Thanks so much for your detailed explanation on what to do. I am ALL OVER it. BTW – love the travel pics – have done a fair amount of riding in Europe and it brought back great memories and gave me some new ideas (not including wrecking my shoulder).
Yes. Visiting emergency rooms in Bulgaria at night is more of an adventure than you really need for a memorable trip 😉
Great site, thanks for sharing it.
Thank you for stopping by and for the kind words. I hope to post new info on how painting goes next.
Is it possible to purchase all this information on a dvd? I would love to have access to this info in my workshop, however my router does not reach that far.
I am just getting started on my restoration, and your information will be extremely useful.
Thanks for coming by and I’m glad my documentation on this project will help you.
May I suggest you just print the documents out that you need? For instance, I find that I can copy/paste a document into Word and then print that out. I don’t have any plans to “publish” other than here in my blog space.
I hope this helps.
Since my earlier e-mail I have purchased a new router and can now view your website in my shop. I have previously restored two /5s which regrettably I have sold. In a move from Ga. to SC last year I gave away all my /5 stuff (info & parts) thinking I would not get involved again. So, your pictures and detailed descriptions are very much appreciated.
Cool beans. My Wi-Fi is strong enough to reach my shop, and I do find it handy to be able to connect to the Internet to browse.
I’m glad this content will be helpful in getting two more airheads flying again.
Inspired by your project (’73 R75/5 Rebuild) I have been looking for a similar bike. I found recently a ’76 R75/6 and would like to buy it. It shows its age, but starts fine and most systems work–except the dashboard idiot lights. The owner is asking for $3,500, and I thought it was high. He turned down my $2,300–but lowered the price to $3,000.
Is this a reasonable amount to pay for this bike? It runs fine, no leaks, and shifts smoothly. I would like to send you a pic, but not sure how. If you give me your email, I could send it.
I NEED your help. I love the bike, but I can’t afford to pay more than what it is worth. I hope you can help me–and soon, before someone else takes it!
Thanks for stopping by and looking at this project.
I really don’t have sage words of advice on what you should pay for the bike. You can always lookup the Kelly Blue Book value on-line:
It’s a starting point for a negotiation. In my experience, blue book value, emotion and negotiation skills drive the final price.
Thanks for the very detailed documentation. I am changing the engine block on my ’73 /5 which experienced and valve lifter breakage. It tore up the bore. But, I found a “short block” on Ebay. So, I’m removing all the good parts from the old engine, and swapping to the new block. Many sub-projects will be necessary in the process. I had previously restored all the top-end, so I have good stuff to work with.
I’ve had the bike since 1985, and it’s got hundreds of thousands of miles on it.
I’ve never pulled the engine before, but have pulled the tranny for overhaul, replaced the clutch, etc.
As an electronics tech, this is outside of my comfort zone, but the first job I got when I left the Navy, was motorcycle mechanic. Didn’t last long….
I will be using your website for reassurance as I work through this job. I am glad I have a 2004 R1200 in the meantime!
Long Live Airheads!
Yes, it sounds like you have a “project” on your hands. It’s easier to be patient when you have another ride you can use.
Best of luck with your project.
Hello, This blog has great content for r series enthusiasts. I would like to ask if I can replicate parts of your blog for Dutch and French BMW r drivers in my region? I would translate and use your pictures as reference. Let me know!
I’m glad the blog has been valuable. Please send me a note directly so we can discuss your idea.
I’ve been enjoying your writings and photos on all things BMW. With 2 of them in the garage as well as a half a dozen other bikes, I am always interested in how others are attacking problem areas. I noticed you had problems on removing the Phillips head screws on your carburators and used an impact driver! May I suggest investment in a set of JIS screwdrivers. I always had a problem with fasteners on a lot of Japanese bikes and ruined a lot of what I thought were Phillips head type of screws – but there not. My screwdrivers would constantly cam out and ruin the screw head until I got a set of JIS screwdrivers. They will even remove previously damaged screws and work well on the European bikes as well. Another area that give people fits is the front brake master cylinder cover on many bikes. Water and brake fluid work together here to create the corrosion that lock the screws – another job for JIS drivers.
From the looks of your RS it needs a lot of TLC. My 83 RT had a problem with the front brakes which turned out to be a buildup of corrosion under the master cylinder reservoir. With the replacement piston/seal part going for $175.00 I elected to RR it myself. If you haven’t gotten into that yet, a .009-.010 E-1st guitar string is great for cleaning out the feed/return orifices in the mastercylinder.
From the looks of projects it doesn’t appear you need too much help from me. Good luck with everything.
I just got back from Denver – sorry I didn’t catch up with you earlier.
Yeap, JIS drivers are on my Xmass list. That said, these were completely rusted so using an impact driver (carefully) was successful. And, as I noted, you can break those tabs off the carburetor. When faced with a similar problem in the future, I’d use my electric impact driver instead of the hammer actuated one shown here.
PS: Re JIS drivers – the “cheap” double-ended screwdrivers found in Honda tool kits are JIS spec! The bits and handles are available from any Honda parts house, my favorite is Partzilla, for about $1.00 each!
Hello Brook, I bought an R75 a few years ago, I brought it home in a few cardboard boxes and have been rebuilding it ever since. It’s a mixture of /5 and /6 bits but the project is comg along well enough. However I’m struggling now with how/where to route cables! I’m speaking of throttle, brakes, rev counter, etc. It’s very crowded behind the headlamp shell! I think some of your excellent photos have almost sorted the throttle cable routings but thge rest remain problematic! Every time I go out I’m looking for R75’s to photograph but they’re pretty rare where I live. Any advice you can throw my way would be much appreciated and would merit a beer or 2, if I didn’t live 5000 miles away!
Keep up the good work!
Martin King, Oxford, UK.
Indeed, cable and wiring routing is fun ;-). I tried to take a number of pictures of the routing when I took the bike apart and tried to show how I routed them when I put it back together. You can find that information here:
61 BMW R75/5 Remove Wire Harness and Electrics
61 BMW R75/5 Install Electrical System
I hope that helps. BTW, even with all the pictures, I still ended up reordering the cables as I went to improve cable routing to reduce kinks and keep lever operation smooth.
I hope this helps.
Hi Brook, really good photos, should set me up nicely! Thanks for responding so quickly and if your annual European wanderings bring you to Oxford I’ll happily buy you those beers!
Well thank you for the kind offer to share a pint with you. The UK and Scotland are on our list of future MC tours. Now we’ve got a good reason to visit Oxford 🙂
Hey Brook – I happened upon your blog and was impressed by the wheel rebuild post for the /5, so I subscribed… I lived in Boulder for a dozen years in the 80s and 90’s, most of those comutting to jobs in Denver – unfortunately part of the problem alone in my cage on I-25 as I didn’t have a bike during those years. Anyways, I ended up in Syracuse and recently sold my trusty ’79 R65 to fund a ’72 R75/5 Toaster barn find – it was last registered in ’82 and only has 35k original miles. It’s in great shape but does need to be brought back to life after a long sleep. One thing I need are tires. For the R65 it seemed easy to find a reference on the net for the correct “oversized” (fat) rear tire. I’ve been searching for something like that for the /5 but can’t seem to find it -there’s a ton of other good info, so it’s like looking for a needle in a hatstack. Might you have decent recommend tire sizes on the top of your head? Thanks in advance! Cheers!
You can try the Metzler tire web page.
Fill in the brand and model and it will provide suggested tire options. They make rubber for the R75/5, /6 and /7 models. I currently have the LazerTech model mounted on my R75/5.
I hope this helps.
Brook, Looks like you gone thru and successfully done some beautiful restores. I’m on the home stretch on my frame-off restore and need some advice. I’m trying to route all the cables and the electrics on the handle bars and not having much luck on my ’75 R90/6. Do you have pictures of the throttle, brake, clutch and electrics routing from handle bars to components? I have not looked thru all your web pages, but if you could direct me in that direction, that would be great. Thanks for your time.
Mike Riley, Westiminster, CO
This write-up should have some pictures of cable and plug wire routing.
On page two of these Flikr photos, there are some shots showing cable routing.
The speedometer and tachometer cables come up behind the gusset next to the steering head and then cross over to the other side to connect to the correct meter in the instrument cluster.
I plan to take pictures of these details on my current R75/6 “freshen up” project in the next week or so.
I shot a video of the wiring routing that will go in a write-up on this topic for the R75/6, but I haven’t had time to create the write-up yet.
I think I’ll use a video to document the cable routing. It’s easier to follow where everything goes.
I hope this helps.
just to let you know that we much appreciate your efforts
and a picture re: a thousand words certainly applies.
I have the same restoration interests and so far have
restored 3 x earls fork BMW’s and a 79 R100RS .
It is a good hobby to give old bikes of that quality a new
life . So often they just disappear . Congratulations on a job well done.
I’m pleased the site has been helpful. I have not done a 60s era project, but they do interest me.
Thank you for the kind words.
just read your ATE caliper rebuild posting. nice job.
when I rebuilt my calipers the dust seals were very tight, i tried both BMW brand and aftermarket. It made no difference and I ruined two of them trying to get them seated in the caliper.
Then I made a wood press block that applied pressure to the entire dust boot uniformly. With a C clamp that worked well.
Apparently your dust boots went in a lot easier than mine.
I too have heard that some of the dust seals don’t fit well. Fortunately, mine did. That said, the first time I put them in they didn’t seem to go in all the way. It turned out that the metal ring the fits against the caliper bore got left in the bore when I removed the seal. Once that was out, the new dust seal went in pretty easy. I suppose if a seal seems to “tight”, you could head the caliper with a heat gun and freeze the seal in the freezer to improve the fit.
Did I miss any posts on what tires you would use on a r100rs Am in process of totally rebuilding a 1979 r100rs.Estate sale previous owner wasnt a good care provider.I really appreciate your web site it has allowed me to tackle projects the easy way, instead of the hard way. Just finished redoing a 1983 r80rt that I have had for awhile. Pushrod seals new rings .Refurbished heads ,wheel bearings,etc,etc love that bike.Loved your articles on cleaning up aluminum . A lot of effort but worth it.Thanks again. Ralph
No, I’ve not posted what tires I chose. That said, I also haven’t posted what oil I chose as both decisions often start a tire or oil debate. 🙂 Chose what you think works for you.
Best of success with the r100rs project and putting mile on the r80rt.
I Purchased a 1976 R90-S From Perry Bushong (RIP) at BMW of Fort Worth in 1978, as a former Navy Fighter Pilot A4’s/Vietnam if it goes fast and makes a lot of noise!! I want it!! Perry Had made an installation of a Turbo-charger Kit on another BMW and i had to Have it!! In 1980 This bike went @ 160 mph and don’t ask me how I know this!!
There is an article about my bike in Airhead E zine from the UK in Volume 1 Issue 6. A friend of mien who is the Manager of HD of WV badgered me for two years to sell him this bike and I finally relented and traded it to him for a 2008 Ducati Multistrada 1100S, He ended up donating the Turbo Beamer to Museum in Australia
I’ve enjoyed reading your stuff in the Owner News. Having restored many motorcycles over my 50+ years of riding I appreciate your attention to detail. I owned and rode a 1978 Silver/Blue R100RS when I lived in Santa Fe years ago, great ride. I currently ride a very early import 1974 R90S that I restored several years ago. I just finished a 1942 HD UL with Hack. Sorting it now.
I have a question totally unrelated to your restorations. In this months Owner News on page 43 is a picture of you standing beside your R100RS in a riding suit that I can’t identify, but like the features of. Can you please tell me the brand/model of this suit. I’m looking to finally move from real old school leather to textile. Thanks, PJ
Thank you for the kind words about the MOA magazine articles.
It’s an Aerostitch Roadcrafter, two piece with about 120,000 miles on it. It used to be a quite bright neon yellow 🙂
Thanks for the quick response and the info.
I building a R100RT to race on the Bonneville Salt Flats and need to replace my main bearings. Is there a good webpage showing the procedure?
Best regards Jim
I have not done that work and unfortunately I have no references to share with you. Best of luck.
Hey Brook… This is hands down one of the most valuable airhead blogs… Saved me in a pinch many a time. Quick question for you. At work I’m writing an article about the motorcycle industry, loyalty, and building new ridership. I’m really curious to understand why the manufacturers don’t play in the second-hand bike spaces, as it seems that is where the real enthusiasts end up. If possible, I’d love to try to connect with you by phone at some point for a quick interview. Let me know if that might work. Thanks for all your work and this amazing resource!
I was reading your thread regard rebuilding the Bing 94/40/103, and have few question to ask you. Can provide me with your e-mail address so I can send you privately?
I’d prefer that you posted them to the rebuild document so others get the value of the questions and answers. It’s very useful to those who use these documents.
–> 13 BMW 1977 R100RS Rebuild & Refinish Bing Type 94/40 Carburetors
Big Thank You Brook for taking the time to help others such as myself. Your postings will be invaluable to me when I get to wire in the electrics on my 75/5 project.
Great info here! I recently purchased a 1972 75/5 and a newbie to road bikes in general and minimal knowledge of motorcycle electronics so this is all new to me. I recently updated the starter, relay and coils so its running great. My question is on the ignition and alternator. Should I consider upgrading these items too? I have looked at some of the products Euro Moto Electrics offer. I live in Florida so don’t plan to add any accessories that would draw more current (ie heated grips) and my rides are short ones around town one or two days a week.
I have read many post of the forums out there but everyone has a different opinion and you seem to be extremely knowledgeable so thank you in advance for your input.
Nice to hear from you, and congratulations for picking up a classic /5 model.
Due to the age of the bike, and to some extent the climate it’s in, you may wish to “pre-emptively” replace the alternator (stator, rotor, brushes, external wiring) along with the diode board and voltage regulator. EME (Euro Motoelectrics) has quality components, as well as complete kits at excellent prices.
BUT, you don’t have to do this is you don’t want to. You can put this off until you have a charging system failure which you will notice since the charging indicator light will alert you to a problem prior to the battery going completely flat, unless it happens on a really sunny day and you don’t happen to notice the dim glow of the light :-).
EME has a kit that replaces the stock alternator with the stock, smaller 105 mm diameter rotor, diode board and voltage regulator. They also have a kit with a nice upgrade for the /5 that provides /6 output (280 w) instead of the lower 180 w provided by the /5. The /6 rotor is larger (107 mm) than the /5. So, there are some options if you decide to do this upgrade. One is to install a new stator cover (which can be ordered with new brushes and all the external hardware/plastic pieces, or not in which case you remove and install them) along with the wiring for the extra stator “Y” wire that helps increase the output of the /6 alternator over the /5 one. If you opt to upgrade to /6 output, I’d invest in the new alternator cover with the new bushes and hardware/plastic components. The plastic brush holder and stator wiring terminal degrade over time due to age and the heat they are exposed to, so they can cause flaky charging system behavior at some point. For the price, it’s a good investment in another 40+ years of smooth charging system operation 🙂
I suggest you call EME and discuss the options (stock /5, upgrade to /6 output) as they are very knowledgeable and always willing to help their customers.
I hope this helps.
As a happy new owner a 93 R100R and member of airheads, awesome post!
Just what I needed for winter detailing duties.
Friday, December 28, 2018
Hi, Brook. Thank you for your attention to detail, including the fact that we all begin with dirty and work toward clean and tidy.
Brook, I built my ’76 R90/6 from parts, beginning with a seized crank, bent valves, twisted frame and forks, empty transmission case but loose gears and shafts that had been discarded, and a wiring harness I patched together. The bike now looks and runs like it had less than its quarter of a million miles. Starts on the first kick, stops, lights work, horn blows; what more could a guy ask?
I’d like to renew the main wiring harness. When I’m done, I’d like to headlight wiring to look like it did originally. I can’t find a picture to use as my goal. Is there a sequence that will avoid crossing wires unnecessarily? Can you get me off on the right foot?
I don’t have enough time in my life for chit chat, so please do not send me unsolicited information or advice. I am father of five children, grandfather to their children, have renovated three properties including a two hundred year old grinding mill that became our home and our B&B. Now I’d like to renew the heart of my BMW electrical system and then head our for a series of trips that will include Maine, Virginia, NY, Ohio, Colorado, Montana, Washington, and California
If I understand your question, you want to know how I would remove all the wires terminating on the punch-down board in the head light bucket, and install a new harness with all the new wires going to the correct punch-down board terminal.
1. Get a picture of the punch-down board. (here you go)
2. Number every terminal on the picture of the board.
2.1 Note the board is color coded to match the wire color code so it’s simple to connect a wire to a terminal in the correct color code family. You can number each terminal in a family, or you can number every terminal with a unique number.
3. Remove each old wire harness wire, add tape with a the correct number to the end of the wire.
4. After you remove all the old wires out of the headlight bucket, match an old wire to the corresponding one on the new harness.
5. Put tape with the correct number on the new harness wire n near the terminal end.
6. Thread the new harness wires into the headlight bucket, starting with the longest first.
7. Put the wire where it belongs and remove the label from the end.
8. Rinse, repeat until you have no more new wires.
I hope that makes sense.
Hi Brook. I just bought a 1975 R75/6 and I’m in need of a left side light/horn switch assembly. I may be able to get by with just a new “yellow” switch that turns the lights on and off. Any suggestions on where I can buy this? Clint
Those seem to be “unoptainium” from BMW. Used ones are often available on eBay. You can also contact Tom Cutter, http://www.rubberchickenracinggarage.com as he may know of a suitable substitution.
I hope that helps.
Saw a post from you regarding the engine plate adhesive, so I thought I’d say hello. I live and work in Arvada (Aim High Property Management in Olde Town), and have a custom ’71 R60/5 that is currently without engine plates. I have the plates but wanted to make sure they didn’t fall off… again. Do you have a recommendation?
Thanks in advance,
I found Silcone Seal seemed to work quite well. It is stable up to 400 F which is way above the temperature that top engine cover will ever get to.
I tried “Gorilla Snot”, which is a 3M adhesive for automobile trim, and was what “knowledgeable” folks recommended. It failed on a 95 F day. The silicone seal has not failed in 8 years.
I hope that helps.
BTW, there is an Airheads BMW group on Down-to-Meet that you can join. We host a number of events every year including Tech Days and Tech Classes.
Thanks for the reply. Which type/brand of silicone seal do you use?
I’ll will definitely look into the Airhead club!
Just plain run-of-the-mill auto parts store silicone seal, clear. I didn’t use RTV, just standard silicone seal.
I have used your great site for a few years now, thank you so much for sharing!
have an electrical issue I haven’t been able to find it online though and thought you may be able to help? When I put the key in, only the red light shows up. I had to kick it to start. All my turn signals and brake lights are out, only my headlight works. when I hit the brakes or turn signals the recharge light in the lower right lights up.
I don’t know electrical really but hoping it is a fuse I would replace or something simple?
Thanks for any thoughts Brook,
Very likely one, or both, of the fuses are blown. They live inside the headlight shell. But, the question is, why did the fuse blow?
The red light is the alternator charging light. The fact it lights when you use the brakes or turn signals, suggests there is a short in that wiring, which is what blew the fuse. If that’s the case, whenever you use the brakes or turn signal, you are shorting out the electrical system creating a large current flow from the battery, so the alternator can’t maintain enough current flow to the battery to charge it.
If you do have a short, this needs to be fixed before you use the bike any further to avoid damaging other components when you use the brakes.
I hope that helps.
I have enjoyed your recent otra blogs and I am curious as to how you power your gps on Gonzo. I just bought a new garmin 396 lmt-s at the new reduced price of $235.00 delivered, and trying to find the best way to get power to it.
Best regards Bill
I like mine to be on when the ignition is off. So I wired it (with a fuse) into the red terminal (30) block inside the headlight shell. If you want it power off when you turn off the ignition, I think there is a spare GREEN-Black terminal (in which case you don’t have to add the fuse as this is downstream of the 8 amp fuse and the 396 only draws 1 amp at 12 volt) or you could add a fuse and use one of the spare GREEN (terminal 15) terminals.
I like to route it to the headlight shell so everything is in one place. YMMV.
I hope that helps.
Hi Brook, always love reading your posts and thank you for constantly updating them with great tips. I hope this is an appropriate spot for me to leave a comment seeking your advice. I wonder if you would do an article on tips making the clutch and brake pulls less stiff? I know there are several journals out there about these topics and I would like to get your take on this? I have a rideable 71 R75/5 that still needs work but I take out on occasions and usually, after a couple hours in traffic, my arms and wrists are cramping because of the workout. I am planning on replacing clutch, brakes, tires, cables etc by myself in upcoming servicing…Last year, I decided to do minor improvement by adjusting/lubing clutch and brake lever cables (contrary to Snowbum’s warning that we should not do this). It was ok at the time, but this spring (my first ride with the bike), I almost could not pull both back! I don’t know if it is because of the cold weather or Snowbum’s warning is haunting me now. Anyway, I am planning to replace all the cables and the components. But I was wondering if you have any other advice? Also want to mention that I have small hands so I was wondering if somehow bending the levers or buying after market levers can retrofit this? Your advice here is greatly appreciated. If you already talked about this and I missed somehow, please point me to a link. Thank you. Henry
My wife had similar problems on her /5. I installed an “Easy Clutch”. It made all the difference.
Having the clutch cable correctly installed with minimal kinks is important. Newer cables have a teflon sheath and lubricants actually hinder easy movement of the cable in the sheath.
I hope this helps.
Hi Brook, yes I have heard about the Easy Clutch. I will look into it after my clutch overhaul and if I find the clutch still too heavy to pull. I also hope new cables will solve both the clutch and front brake pull. I will keep you posted if whenever I ever get to accomplish this. Best regards, Henry.
And, I should have pointed you to the article on adjusting the front brake. Getting this right makes a large difference in the effort needed to stop the bike.
34 BMW 1973 R75/5 Install Front Brakes
Hi Brook, yes I have read your journal on the brakes when I last attempted changing the handlebar and ended deciding to lube the cable. I will read again when I proceed to change the brake shoes and cable next time. Thank you for the reminder. Regards, Henry.
Easy Clutch is definitely the way to go. I installed one on my rebuilt R75/6 and could hardly believe the difference it made.
Hi Martin, thanks for the recommendation. Will definitely look into it. Regards, Henry
Henry, one thing I meant to mention. If you do go down the Easy Clutch route make sure you have a really good cable cutter. You have to cut off the bottom end of the clutch cable then thread it into a brass barrel. It’s a tight fit and if the cable end isn’t cut really cleanly you’ll struggle to get it in. Ordinary pliers won’t cut the cable well enough, they’ll flatten it slightly and leave loose strands. I had cutters for stainless steel boat rigging, a bit over the top but it did the job. Don’t be put off the solution though, it really works!
Hi Martin, thanks again for the advice and repeating encouragement. I am definitely interested. Now I long to get some wrench time to replace the clutch then see if the Easy Clutch is the way to go (I am getting sold already)….Please allow me some time to get into this, I will definitely keep you all posted. Best, Henry.
I really enjoy your videos. I have a ’79 RS definitely looking for rejuvenation at some point. So, while watching one video you scanned towards “Gonzo” and I saw the wind deflector… Could you please advise on the manufacturer? I have a terrible time with wind. Tried the Laminar lip with not much luck. Also I run stock Metzlers. May I ask what you are riding on?
Here is a link to one of the screens made by MRA available at Twisted Throttle. The one on Gonzo uses clamps rather than bolts.
Gonzo has Pilot Actives, but they are very hard to mount as the side walls are very stiff. I’d have a shop do the mounting.
I hope that helps.
Thank you so much for posting these guides. They’ve been invaluable to me as I try to navigate my way through a rebuild of my dad’s 1981 BMW R65. I’m moving forward at a snail’s pace but moving nonetheless.
I’ve reached the stage of reinstalling my wheel bearings. I’ve read your post on the 1983 R100S at least a dozen times by now and am unfortunately at what seems to be an unconquerable hurdle in setting the pre-load. It won’t pass 400 Grams of resistance and I don’t know if I’m doing something obviously wrong.
Any help would be greatly appreciated. If possible to send me a private email, that may be best.
Thanks again Brook!
I’m sorry to hear your having a problem. I’ve not worked on any of the R65 bikes, but AFAIK, they use the same wheel bearings.
The grams aren’t what’s important, but the INCH-Ounces of torque required to spin the bearing. Since I don’t know the diameter of your sleeve, I don’t know if you can’t get the torque low enough or high enough. Perhaps you can tell me what INCH-Ounce values you get for each wheel.
One thing I have noticed in the two sets of wheels I set the pre-load on was that if I put no shims in, the torque required to spin the bearing was quite high, so I would expect yours would behave the same way.
BTW, it’s helpful to me if you post your questions in the comments of the specific document you are using so I know exactly which one you are looking at.
I’m installing a used RT fairing on my 85 R80 and have a couple of questions.
What should the 2 bolts that secure the frame to the bike be torqued to?
With the frame in place the steering lock to lock has been reduced. Is this normal?
Many thanks, Jim
If you are referring to the two short bolts that screw into the steering head, there is no published torque. So, “good and tight”.
Yes, the fairing restricts the amount of handlebar movement on both the RS and RT fairings. Therefore there is a bolt (M6x22) with lock nut that is installed in the hole at the bottom of the steering head to restrict handlebar movement enough that the ends of the handlebars don’t scrape the inside of the fairing.
You can see that here:
I hope that helps.
Thanks Brook. 2 thumbs up 🙂
Hello Brook. I’d like to thank you for all your online contributions and the help you extend to anyone asking. Im more or less finished with my 1971 R75/5 police bike. The work I’ve done on it includes basically everything, except a cam chain change.
The bike was in service from 71 to the end of the 70’s I presume, with the danish police force. In this configuration it would to my knowledge be painted in white (fenders and tank), have a toolbox hole in the gastank for radio equipment, possibly have a short seat with more radio equipment behind the officer, police lights and enclosed ignition coils in a tin box to avoid radio interference. Police bikes were either 75- og 60/5 at the time. Before that they used /2 or /3 bmw’s and before that, the Danish Nimbus model C Sport… of which I have a 1950’s example in blue. #9615
My BMW was sold to the civilian market to its “first” owner in more or less stock shape. He mentioned the engine was “done”, passed it along to me and showed a repaired hole the size of a fist on the right side of the crank, behind the cylinder. He then put a 1974 900cc engine in it at the start of the 80’s. I bought it with what looks to be a twisted rear swingarm (Which I havent resolved and isnt noticeable on the road), painted in a rusty Bordeaux red, a worn/dry rear drive and stuck rear shocks. I didnt like it at first, but with every fix and upgrade it received it rode better and grew more and more on me. Different aftermarket parts are numerous and fairing options started to appeal to me. I found and bought a Gläser sl5/sl6 fairing from a guy in Leipzig, and got /6 sidecase panniers. The Crauser luggage rack featured a 50’s Craven fiberglass top box, which I dismantled in favour of making my own fiberglass (bullet end) top box, which is made to compliment the panniers and the overall shape of the bike with the fairing, along with practical spacious room for touring.
Dare I mention drag? I like the idea of a streamlined motorcycle, and I have measured a best fuel consumption of 21km/l / 49mpg unfaired. I hope Craig Vetter knows he’s in my thoughts, since he inspired me to build the bike in a touring/aerodynamically efficient manor. I might gain nothing, or a single mpg, but thats all ok. Still exciting when I’ll do some more testing.
New shocks, tires, valve job, honing, rebuilt front end and a 1977 smooth-sided five speed gearbox was added, to increase joyful allround riding.
I am still sorting out a few aerodynamical challenges in relation to the windscreen, but I’m fairly sure I can make it work. The rear end might always be crooked (Rear tire is twisted 2-3 degrees compared to the front tire), but thats ok. Might even do an unleaded conversion sometime or try and change the crank ventilation system somehow.. Or not, it all works great as it is. Following the completion of this build will be trips to Sweden, Norway and even more.
So thanks Brook, I couldn’t have done it without you. Below is a few pictures of me and my finished(-ish) bike. It looks 70’s funky (or ugly, depending on taste). Hope you’re doing well and will keep doing what you love in the shed.
-Christian Bjørnholdt, Jutland, Denmark.
First of all, WOWWWW!!! That is a fantastic looking rebuild. I particularly like the fairing with the customized rear trunk you made.
And you are the lucky owner of a Nimbus. That is very cool. 🙂
You obviously have patience and passion for what you do. If in some small way my publications were helpful, I’m very pleased, but the result is all due to your craftsmanship and your vision. I congratulate you for your perseverance and applaud the one of a kind build you created from an abused airhead.
I hope the two of you tour together for many years and kilometers.
All The Best.
Thanks for all your very clear articles and movies. They are for sure a big help for me in the restoration of my 1974 R60/6.
I am looking for the item where you restored the BMW name plates on the engine casing. I know that I did see that once, but I cannot find it again. Can you help me out?
Henk from The Netherlands
I have been putting all the refinishing, repairing and painting work on the 1983 bike into a single document as I go along.
–> 51 BMW 1983 R100RS Repair, Refinish, Paint
I believe you will find what you are looking for there. And, best of success on your restoration project.
Thanks for the link. But I have in my head that you have also described somewhere that you taped the area around the name plate and sprayed the complete nameplate and later sanded the the paint of the characters with different types of sanding paper in order to remove the paint. I was looking for that one, but still cannot find.
Well, that’s what is shown for the technique I used to paint the inner timing cover and the document notes I used that technique for the top engine cover.
Your description is what I have done on a previous build when I used sand paper to remove the paint on the letters. The paint scrapper is more efficient and controllable, but either method to remove the paint works.
Just found your page. What a wealth of information!
Trying to patch up my 1973 R75/5 and when I went in to replace a fuse and the turn signal indicator bulb, noticed a grey/brown (or grey/black?) striped wire coming off the headlight with the stripped wire end not connected to anything. Do you happen to know what this wire is/where it is supposed to go? Quite a rats nest in there….
You should get an electrical diagram for your bike as it can be quite useful.
I wrote up some information about the /5 electrical system that maybe helpful to you
/5 Series Circuits
/5 Series Electrical Components
The GREY-Black wires are the parking/running lights. The one that’s loose inside the headlight shell goes to the parking light bulb.
I hope that helps.
Thank you Brook, much appreciated. The grey/black is currently connected at the parking light, it’s the other end that’s loose/causing me trouble, do you know what it connects to?
It should go to another GREY-Black wire inside the headlight shell. I show that in the documentation I sent you links to. Read through the section on GREY-Black wires in the “/5 Circuits” document to learn what goes where.
Yes sir! Thank you so much. The other end was pulled out of the fuse connection. Back in business!
Hello Brook, I have a rebuilt R75/6 which, thanks to your excellent videos, goes pretty well However I’m getting oil leaking from the rubber boot on the back end of the gearbox. The boot itself is fine so I’m assuming it’s the oil seal on either the gearbox or the final drive which needs replacing, maybe both! My question is a bit of a dumb one I think but I’ll ask it anyway. Am I right to think there should be no oil at all getting into the boot since both ends of the drive shaft are sealed?
Best Wishes, Martin
If you are talking about the boot between the transmission and the swing arm tunnel the drive shift fits inside of, a leak there is often fixed by adjusting how you seat the boot on the swing arm. I’ve had them leak and adjusting the fit where the rear hose clamp goes fixed it.
The drive shaft sits inside the swing arm tube. The tube is not “sealed” except by the transmission/swing arm boot sealing and the at the rear, by the rear drive gasket sealing. The tube has gear lube in it and it sloshes around inside the tube as the swing arm moves up and down. So, the boot has to seal against the swing arm for lube to not leak out.
I hope that helps.
Thanks Brook, I’ll have a poke around with the boot positioning. Take care, Martin
I love your videos. I wished I was your neighbor and could work and learn from you.
I love the air cooled boxers. I own a R100GS PD from 1993 and a R1200GS Adv from
2011. Both of them mean a lot of fun to me. If you are heading to Germany in the future let me know.
Besr regards from Germany
Thank you for the kind words. It would be great to be able to travel to Europe again. Perhaps we can do that in the not too distant future.
Stay well and ride long.
I would also highly recommend TURKEY for riding if you come over to Europe once again. It is a beautiful country with amazing people and some magic places, Cappadocia for example. There are some Vlogs about Turkey in youtube.
Hi Brook — First time leaving a post here though your videos have been hugely helpful to me throughout the years! I have run into a problem I have not seen before.
I am replacing the speedo cable on my 83 R80 RT. I thought the hard part would be connecting it at the transmission case but thanks to your video it was a breeze, However, what I thought would be the easy part, pulling the cable from the speedo itself, is a problem. I loosened the nut and pulled it back to find the the pin pretty much stuck inside the back of the speedo. I haven’t pulled too hard, but it’s definitely not coming out easy (the speedo was jumping and making a rattling sound, which is why I replace the cable in the first place).
So my question is: Can I just pull harder to get the damn thing out? And what is the adjustment dial on the bottom of the speedo for? Sorry for the long message but I can’t find any information on this anywhere, Clymer or otherwise. Thanks!
The cable has an inner cable with a square pin that fits into the bushing on the speedometer shaft. If the cable won’t easily pull out after you backed the locking nut off, it’s possible the square pin has rounded and has become jammed in the bushing. More force seems reasonable to get it loose.
If the bushing on the speedometer shaft is damaged, then it needs attention. From my past experience, when the speedometer starts making noise, it can be the cable binding, or it needs to be rebuilt due to wear. If the speedometer needle still jumps after you install the new cable, you need to have the speedometer rebuilt. If you let it go, it’s not uncommon for much more expensive damage inside the speedometer.
So, you may want to have it rebuilt. I have used Palo Alto speedometer (http://www.paspeedo.com/), and an independent who does very good work, Terry Vrla ([email protected]).
The knob on the back of the speedometer resets the trip meter.
I hope that helps.
Thanks a ton, Brook. I’ll try to jimmy it out with a little more force this time! Nothing to lose, I guess, if the speedo might need a rebuild anyway. I rode if for about a half hour when I first noticed it, and was advised not to ride it again until the cable had been changed. Hopefully it does the trick. One way or the other we’re heading into the off season so good timing to send it in for a rebuild. Thanks for the tips, MW
I am Seung-yeop Nam living in Korea.
My nickname is Da Vinci.
I never thought I’d be riding a motorcycle.
By the time I was 50 years old, I wanted to feel free, so I dreamed of traveling the world on a motorcycle.
And I bought a used BMW r1150GSA.
Now I have the R1100GS and R1150R more.
In fact, I am very interested in the older R100 series, but it is difficult to have it in Korea.
There are no used products, and it is difficult to import used because of emission certification.
So while I was thinking, I became interested in installing a carburetor by remodeling the oil head.
I have 2 sets of bing 94 and 1 set of 64.
While searching the internet for information to rebuild Bing carburetor, I found out your blog
I am grateful for sharing such a vast amount of information so kindly.
Thank you again.
Best of luck on your project. I’m glad my documents are helpful to you.
I cannot tell you how much you, Dan from cycle works and Norman from EME are my guiding lights through my projects.
I’m starting a ‘74 R90/6 that has been sleeping in a barn for 35 years after a solid 175,000 miles on the road. An old bike that was well maintained, like the original owner said to me… but we’re pass that now 🙂
I would like to send you a couple of pics with measurements of the crankshaft of this old R90/6. Everything’s is pretty acceptable but the connecting rods journals are a mere 0.002 mm below std specs. I’m a bit resistant to the idea of having it machined especially because of the press-fitted counterweights…
If ever you wanna chat about this it’ll be wonderful!
(I’m From up north in Canada)
Regards and congrats again on the amazing stuff!!
I agree that Norman, as well as Matt and Jodi, at EME, and Dan at Cycle Works, are “good people”.
As I understand it, you should NOT grind the journals on the crankshaft as that will remove the heat treated hardened surface and destroy the crank. There are different size connecting rod bearings to accommodate some wear on the pin.
I hope that helps.
Thanks Brook, I’ll follow that lead👍
Quick question I’m sure you know the answer: are the center stand receiving tabs welded on the frame supposed to be straight or bender inward? 1974 R90/6 frame
Thanks Brook and happy and safe holidays.
I believe they should be vertical and parallel.
Thanks for your answer, I’ll find a way to get them straight again and let you know.
Happy holidays !
Was curious if you work on others airheads or only your personal projects?
Appreciate your time,
I work on my own projects and I have helped others work on their bikes. I don’t do work for hire, but I am willing to help interested owners expand their “hands-on” knowledge from time to time.
I watched your videos on the R80 resto. I want to install the seibenrock 1000 cc kit on my ‘94 R80RT Euro spec. I noticed you had the heads specially ported for the bigger cylinders. Do I need to upgrade my heads to ensure the bike runs right? I don’t plan on dual plugging either, is that a mistake? Should I stay with stock carb/jetting? I have 353/354 carbs.
I think you may have confused me with someone else as I have never done an R80 restoration, nor have I any experience with the Siebenrock kits.
I have the same exact question but for a ‘74 R90/6
Hi Brook, thanks for your vids and blog…I am learning a lot!
I put together a spread sheet in Excel to duplicate your Oil Canister Shim calculation.
I was wondering if you could clarify how you calculate how you go from 5% for one shim to 13% for 2 and 21% for 3 in your video?
I did the calculation and got 5%, but am unsure how you went forward from there.
Thank you in advance for your assistance!
I show Oak’s formula next to that part of the spreadsheet. The percentages are due to the combined thickness of 1, 2 or 3 shims where in my case the shim thickness (S) is 0.3 mm. The spreadsheet calculates how much the white O-ring will compress as the number of shims goes up, so in each column, I multiple (S) the number of shims and the formula computes the percent compression for that number of shims.
I hope that helps.
Thank you Brook, I appreciate your clarification and prompt reply! Safe travels!
Hi Brook –
Excellent information, which is proving invaluable as I resurrect my ’83 R100RS.
One question: in “34 BMW 1983 R100RS Install Front Brake System|Mount Caliper And Attach Brake Line & Hose”, you state “The bleed valve fits in the hole closest to the wheel.”
On my bike (which I believe never had the front brakes disassembled), the bleed screw is on the outside. Also, my BMW workshop/service manual (March, 1982 section 34 11 000) appears to also show the bleed screw on the outside.
What is the rationale for installing the bleed screw on the inside, given that having it on the outside makes bleeding easier?
Thanks again for a great series of articles – these are an important resource for all Airhead owners.
Since the brake fluid hose and the bleed screw holes are connected, it won’t matter which one you put the bleed screw into.
First of all, I wanted to thank you for this wonderful documentation work.
A year ago I bought a scrapped motorcycle and one of the reasons that made me buy it was your videos. The detail of the information you provide, the quality of details and the exhaustiveness of each of the steps, all of this, has made me encourage me to restore the bike.
Thank you very much for your effort and greetings from Madrid (Spain)
Thank you for your kind words. I’ve ridden in your country before: through the Andalusia region, and Barcelona through the Pyrenees. What a beautiful place for motorcycle riding.
I wish you the best of success on your project.
Thank you and Snow Bum for the countless hours you share with the rest of us.
“Experience is where you take the test before you learn the lesson.”
Thank you for the compliment. Happy Airhead wrenching. 🙂
I’ve religiously followed your blog regarding transforming an ’83 R100RS to a RT and have benefited greatly from your documentation.
It so happens I also have a blue ’83 R100RS that I’m “refreshing”. I came across a photo you took of the rear wheel splines where maybe 40% of the spline appears to have been worn away. Perhaps not surprising, about 25% of mine is similarly worn.
I couldn’t find a discussion of the worn spline in your blog and wondered what if any action you took to repair or replace the damaged spline.
I’m glad this material has been helpful to you on your project.
I did nothing to the splines based on the advice of Tom Cutter at Rubber Chicken Racing Garage.
Love your page! What a great resource.
I’m on triage this morning. Pulled the 1973 R75/5 out and the battery was weak, so attempted to jump and, in a moment of knuckleheadedness reversed the polarity on hookup. Needless to say, smoke ensued from under the tank, immediately pulled off the cables, but damage done. Any idea what things might have fried from this and where to start the diagnosis/what to check for damage? Feeling very very stupid this AM….
OUCH!! That hurts.
I would carefully inspect the entire main wiring harness for burned insulation. This can occur on wires under the black plastic sheath, you you should remove that for a complete inspection.
Then, check all wiring inside the headlight shell for any damage. If either of the fuses blew, then the GREEN-Black wires or GREY-Black wires should be carefully inspected as they may have charred their insulation before the fuse(s) could have blown.
Component failure could have occurred, but that’s not something you can find by just visual inspection. That said, if you find charred insulation on a wire going to a component terminal, then that component could have been damaged.
You can verify that the coils are working with an ohm meter. If you get infinite resistance across the primary or secondary (spark plug wire terminal) then the wire inside melted.
To summarize, be methodical and take you time. Start with the wiring and repair it where needed. Then you can put power to the bike again and verify if any components are not working.
Again, I’m sorry to hear about your problem.
Thank you for responding. That’s about what I thought, be methodical and inspect all the wiring and electrical components end to end. Smoking under the gas tank made me suspect the electronic ignition or the coils took some damage. Major project from a dumb mistake. Got my work cut out for me here….thankful to have your detailed online reference materials available right now!
Any advice on a cockeyed fairing that resulted from an ignominious spill when I first got my bike and hadn’t replaced the OEM kickstand that came with my ’83 R100RS?
My boot broke the lowest attachment point on the left side in the fall, and the fairing seems to have shifted up and to the right from that point. You can see the change in alignment in the gap between the panel that contains the voltmeter and clock and the part of the dash with the RPM and speedo. In addition, my right knee comes into contact with the trailing edge of the fairing on that side more frequently than on the left.
Some have suggested strong-arming the upper fairing, but that seems like I’ll just be forcing something back into place without addressing the issues on the lower left side. Curious about your perspective.
I’m sorry about your tip over. It sounds like the fairing brackets are bent. There are three of them and I show all the details in these two documents; the first shows removing the fairing and the second installing it.
46 BMW 1977 R100RS Remove, Disassemble Body Work
46 BMW 1977 R100RS Assemble Fairing, Dash, Instruments and Windscreen
I would not try to push on the panels to straighten the brackets as you will likely break the panels. I would take the panels off and try to straighten the bent bracket(s).
I hope this helps.
That helps a lot. The input I had received was to move the fairing as a unit, or just bend the top bracket into place. Those approaches seemed risky (breaking a panel by pushing) or incomplete (only solving one issue and creating stress throughout the fairing where the issue wasn’t addressed.
I’ll reserve some time to review your documents. Many thanks!
Best of success in getting the fairing square and true again.
Hello Mr. Brook,
Don’t know if this is your first name or last name, but I strongly believe this is the only info missing on your site. I’m extremely impressed with the work you’ve done here. And this is not a hollow phrase: I’m building 2 r100rs from 79. One came in boxes. I prepared very well by getting all possible documentation: Clymer, BMW manual, Haynes and many more. Also on the Internet I’ve got numerous sites saved (Snowbum, realoem.com, …) but at the end I find myself using only 2 sites and no books: your site and realoem (for some details not on your site). Just to say: your site is perfect for everybody: video’s, pictures, text. Something for everybody. As compared to Snowbum’s site he doesn’t even come near to yours: he has probably much more info but does not succeed in communicating it (in my opinion). I don’t want to spend days reading, but that’s me and I don’t want to be negative regarding Snombum’s site (he is very well respected and I believe this is correct) but he can’t compete with yours. Keep up this fantastic job. It’s been (and still is) an eye opener for me. I’m an IT guy with no technical background, but thanks to you I managed to built an RS from the bare frame on. Many thanks again
Thank you for you very kind words. Much of what I learned came from Snowbum’s materials. It is a great, and quite deep, archive of information. I’m very pleased this content helped you get two more RS bikes back on the road.
Stay well and ride far.
PS: My first name is Brook and the last name is Reams.
Then i also need to thank you for molding the valuable info of Snowbum into something I can understand. Thanks again. Enjoy the weekend!
Hello Brook, thanks so much for this website and wealth of information. I have a question about wheel bearing preload (‘84 R100 snowflake wheels). When installing shims to adjust preload, why wouldn’t you put the shims in before the wedding band? Seems they would be more securely retained in that position. I haven’t started on these wheels yet but I thinking about this I do wonder.
It’s easier to adjust the pre-load with the shims on the outside. They aren’t going anywhere with the dust seal installed.
–> 36 BMW 1983 R100RS Replace Wheel Bearings
I thought if the shims are in the pocket behind the wedding ring then there is little chance for them to shift when inserting the axle while installing the wheel on the bike. I’m using the shim kit from Cycle Works but using all the shims in the kit the preload is still too high. I guess I’ll need another shim kit. I did check, seems that the outer races are fully seated into the hub of the wheel.
Or you can get a longer wedding band (part#’s starting with 36 31 1 230 78x where the x is a digit) so you don’t have a lot of shims.
Hi Brook ,On my BMW R100S 1977 I have a problem, the blanking screws in my Bing carbs are stuck fast, heat and penetrating fluid have not helped, i have been thinking about a number of options,i could ignore it and make the use of a carb balancer impossible,or i could drill out the screw and cut a new thread, or i could drill a hole through the center of the screw, use a carb balancer and then blank off the post, have had this problem? or anyone you know?…any advice gratefully received.Ian
I’ve not had that problem before. I might try using a small pair of vice grips and grab the perimeter of the screw head to see if I can get it to budge.
I’ve heard of drill bits that have the helix reversed. So as it cuts the hole, it turns to the left. A very small one of these might break the screw loose. That said, the bit would be quite thin, so if I tried that, I’d be very careful not break the bit off in the screw.
Harbor Freight shows they have a set of these drill bits down to 1/16 inch diameter.
I’m sorry I don’t have any other help for you.
Yes very small the hole is only 2mm so the biggest drill size will be 1.5mm do not know of anyone else who has had this problem, cannot find a small enough eze-out, and i do not want to damage the carb, will check out the left hand drill option, thanks for the info. Regards Ian
what a amazing blog you ave here, lots of good information.
I´ve just bought a R75 from 1973 where they took away a lot of parts to loose weight for competition purpoes.
I´m going to try to make the bike street legal and wonder abouet the rectifier (diode board).
It seems that some Voltage regulators have a Rectifier built in.
So my question is: Is it possible to skip this rectifier (bmw original part) )and just go with the Voltage regulator that have the rectifier built inside?
Jan from Sweden
You can do that, but you will also have to supply current to the Generator light in the instrument cluster as the current flowing through that bulb also supplies current to the alternator rotor to energize it. Verify with your supplier that they have a way to power the alternator rotor.
You can read more about this here.
/5 Series Circuits
/5 Series Electrical Components
I hope this helps.
i have been driving my 1977 r100 since new , now has 165k miles on it. all original. yes it burns and leaks oil and i wonder about the timing chain condition. My comment /question has to do with the amount of fork oil. When filled to recommended amount i experience a very stiff uncomfortable ride, so much that i have removed the forks and
checked on a lathe for possible bends,- nothing found. Solution is to just put less oil into forks, about 1/3 less than specks , problem solved. I have other riding buddies (with same model) that have complained about the same thing, one even sold the bike out of frustration. This was not an issue with post 1982 models which i also had.
Any ideas here?
i totally enjoy your contributions to the care and mailtenence of these bikes, i even read posts on repairs i’ m not making. my first beemer is 1962 which i bought new and still have. keep up the great work
I would evaluate the forks for stiction. I show how to ensure the fork tubes are aligned in this rather long article.
31 BMW 1977 R100RS Install Steering Stem, Front Forks, Telefix Fork Brace and Toaster Tan Top Brace
Wow Brook, You are so detailed and thorough. My kinda guy ;). I’ve recently acquired a beautiful ’81 R100RS from the original owner with under 29k miles. I’m looking for a tech that’s detailed and particular like yourself. I live in Santa Monica, CA (outside of LA). Would you know of a professional, experienced tech out here that you could get me pointed in the right direction?
Contact Ran Bush, who is one of the Airhead Beemers Club Air Marshals for California, for a recommendation.
–> [email protected]
You’ve reached the perfect place to do your project: read, watch and listen. It’s all here. Just prefect. I built mine based on Brooks clear info. I’ve got a lot of other sources online and of line, but i found myself always navigation on his site. Succes!
Thanks for that, Luc. I suspect you are 100% right! I intend to pay close attention 🙂 Cheers!!
Sounds wonderful. Not sure what an “Air Marshall” is but sounds like an honorary title/assignment :). I’ll reach out to Ran and let him know you sent me.
Thank you ever so much!
Looking forward to reading up on all of your blogs, vids, etc. You are an inspiration…
I picked up a 1983 R80RT and am using you write up to reinstall the faring and dash. Thanks for the tip about using the nylon bolts for the dash. When I went to your source I found it was a 100 count to a bag. No one else had the fasteners in black so I sourced some 1/4″ black anodized aluminum screw binding posts off EBay. Ten to a package so you can loose a few. Still a pain to install but you can push the post in from the back of the fairing and screw threaded part from the front. Added advantage is the head is a very low profile. Thanks for all your effort you have a great site and resource.
I have a 1982 R100T. It has RS body work and until this weekend a drum
brake in the rear. I have been collecting, powder coating, plating parts needed to convert to disk for years. This past weekend I completed the project.
One thing that concerns me is that when I removed the old final drive, oil
started to seep from where it connected to the driveshaft housing. I drained the final drive oil to prevent a mess. Is there oil in the driveshaft housing that I need to replace? Also, what is the oil capacity for the final drive and what weight is recommended?
Thanks – Dave
The transmission, swing arm and final drive all use 80w-90 non synthetic gear lube. So the swing arm tube has gear lube in it which is what drained out when you removed the final drive. You can check the Haynes or Clymer manuals to see what the correct fluid amount is for your swing arm and final drive. IIRC, the amount changed when the swing arm and final drive design changed.
Brook, I’m a reasonably long time lurker but felt it time to reach out. I’ve no real bank of knowledge on BMW’s but in the end most things mechanical respond to the same things. It is the brand nuance that I lack here so while I’ve been taking care of a friends 78 r100rs (1080 miles since new) today it has sprung a leak that I need to fix. An electricity leak. I’m next to useless with electrics but good at following direction and reading diagrams which is what gets me by in this arena which brings me to you.
The bike does not appear to be charging (the dash gauge shows at best 12v but then it lives on a battery tender). So before I tear the bike apart, do you have an order of items I should check first? My slim thoughts run along this vein but am wide open to those with brains:
1) Run engine and check charging at battery.
2) Failing any sign of charging, verify fully charged battery and do a load test for battery condition.
3) Pull hair out as that is all I really know. OK, I do know a few other things but would like the opinion of someone familiar with the bike to help direct me so I don’t waste the owners time.
I love to read and am happy to follow links and suggestions so I look forward to your thoughts when you have the time.
There are documents about the electrical systems on my website that may help you in you diagnoses.
Airhead Electrical Systems
That said, your initial diagnosis tests make sense, except for #3 as that hair will foul up your coffee or beer. 🙂
If you find the battery good, I would check common failure points in the charging system. I listed them in an order that reflects easy to test and/or most likely a point of failure.
1. Voltage regulator has failed
2. Brushes worn too much and need to be replaced.
3. Rotor has shorted or is open.
4. Diode board damaged.
5. Stator has shorted or gone open.
I have documents on how to replace brushes, the rotor and how to test the diode board.
12 BMW 1973 R75/5 Replace Alternator Brushes, Paint Starter Motor
12 BMW 1977 R100RS Replace Engine Electrical Components
12 BMW 1983 R100RS Check Diode Board, Replace Rubber Mounts
To test the voltage regulator, this information from Bob Fleischer (aka Snowbum) should help you
I hope this helps.
You so rock. I’ve perused some of your docs and can’t thank you enough for them. Your step by step will help me find the trouble before Christmas 2023!
I’ll keep you informed just for grins.
Brook, not sure you got my note the other day as I have a new email address. Im sending this from my old address which still works just fine. Long story short: Why would the Gen light never illuminate? And if it is not, from what I’ve read I should look at either the bulb or the circuit the bulb is part of in the cluster? Other than age, this bike is young with 1041 miles on the clock(I just checked) That’s it, thanks for everything, sincerely, Price
The alternator rotor could have a broken wire. The bulb could be burned out. A wire to the bulb could be broken, or not connected. If the bulb is not lit, your alternator is not going to charge the battery.
You can look at my set of electrical explanations for more information about how the alternator circuit works which should help you find the cause. Airhead Electrical Systems
Brook, thanks and I will look around for failures if not the bulb itself. Laughingly, what should have been an easy look-see at the bulb has turned into a project getting the speedo cable off of the speedo drive just to be able to open the instrument pod. Of course right? I will also address the silliness of the bulb failing causing the charging system to stop doing its job. Sometimes I wonder about the Germans. I get to say that since my wife is one! All the best, PC
Thank you, thank you, thank you! Your blog is truly extraordinary! The time and effort you’ve put into sharing your knowledge, especially in such an approachable and humble way, is as generous as it is admirable. In it’s own way, this is an exquisite example of people being their best- earnestly giving without intent or expectation of gain or reciprocation. I appreciate the knowledge you’re been willing to share, admire the way that you’ve shared it, but am in awe of the dedication in doing so. Really above and beyond on many levels.
Thank you very much for your kind words. My goal has been to provide the knowledge I received from many experts who have helped me. I wanted to publish this knowledge for free online and write it from the perspective of an amature hobbyist, me, so that other hobbyists who love their airheads can use it to keep them flying. I’m pleased this material has been helpful to you. 🙂
Good day. Last year (at the tender young age of 61) I finally got my dream bike…an R100RT. It’s a 1981 that apparently started life as a CS. I love this bike. It runs great, rides like a dream and fits me like a glove. This is my 4th BMW. I have had a R60/6, an 86 K100RT and a 96 R1100RT.
I also owned a couple of Yamahas and a pair of Honda CB900C’s.
The R100RT is my favorite by far.
It has taken a bit of work to get to know it and have it running just right…and your site and Youtube channel have helped immeasurably in that effort. For example…I had never heard the term ‘stiction’ until I heard you say it. Good thing too…because my forks definitely had plenty of stiction. Turns out, it was from a slightly misaligned, after market, fork brace. A bit of adjustment, and the front end strokes like butter.
You and Snowbum’s site, have kept my bike on the road.
One of my next projects is to install a stock oil cooler with thermostat. In that effort, I bought a housing off of ebay. Unfortunately, the expanding element was damaged.
Would you happen to know where I could source one for a reasonable price? I figure if anybody would know…you would.
Thanks for all the help you have already provided.
MAX BMW parts fiche shows the “expanding element, part# 11 42 1 259 488, for about $41.00.
I wish you the best on your project.
First off, Thank you for all you do to support the community of Airhead owners. Your website and videos have been invaluable to me as I have learned to repair my 71’ R75/5.
My question is in regards to repainting my /5 gas tank. I’ve looked through your article when you repainted your /5 blue. I noticed you didn’t paint the filler neck area on the tank and I’m wondering why and also how you treated this area which appears to be bare metal by the photos.
I’ve seen bikes with this area painted and not. I know there would be a transition area where gas could possibly get between the paint and metal causing it to blister. I assume this was something you considered in your approach. Wouuld be interested to hear your thoughts on dealing with this area on a paint job.
Thanks again for your generosity in time.
I tried using epoxy on the bare metal as an experiment. The epoxy failed and flaked off, so this technique does not work. So far, there has been no rust of the neck. You are correct that I was trying to avoid paint failure inside the filler neck. So, I am not sure what the best approach is for the filler neck.
Brook, thanks as always for your help. At the moment I’m still stuck with the no Gen Light bulb issue so no charging. However I need your suggestions as I plod forward.
As a reminder, my 1978 R100RS has no Gen Light when ignition is on or the engine is running slowly and the battery loses its charge pointing to the alternator not coming on line. No “excitement” in its poor life.
I’ve done alternator tests and the guys at Euro Motoelectrics feel the alternator is good so look elsewhere.
I’ve pulled the Gen Bulb from the gauges housing to test it and it lights up on its own so is still good to go. I reinstalled the bulb and have tried the test that claims to verify if the bulbs circuit is complete by pulling and then grounding the right side alternator brush wire (as seen from the front of the engine). At this time the Gen light is supposed to light up but still does not which points to some wires not completing the circuit to the bulb?
I’ve decided that since at least two of the four bulbs in the dash that share half of the same power circuit as the Gen bulb do light up when ignition is turned on (Neutral and Oil P in this case), tells me that at least one side of the Gen bulbs power equation is functioning.
Now looking at the wiring diagrams found on this site, and unless the Gen Light bulb is not contacting both sides of its socket correctly, (and having looked at it I’d say it is brand new) I feel I can ignore that functioning half of the equation right?
Per the diagrams, the other side of the Gen Bulb gets its feed via a wire that is connected to both the Diode Circuit and the voltage regulator. Not being an electrics guy I’ll have to presume that this means either the Diode board or the voltage regulator are shorted? I have not tested either the Diode board or the VR but will soon enough.
Again, electrics make no sense to me but I am a plodder so will figure it out. If however you have any suggestions, please let me know them. As in, forget the Board and or the VR as they do NOT help power the Gen Bulb. That kind of thing!
Meanwhile once I figure out how to test both the voltage regulator and the diode board I may have my answer.
All the best, Sincerely Price
Another item to verify is that the brushes are contacting the alternator rotor. If they wear enough they won’t contact the rotor copper rings.
Indeed, finding the problem is an extended task of elimination by testing.
The BLUE wire from the bulb connected to the voltage regulator (D+) terminal and the second BLUE wire on the (D+) terminal that goes to the diode board could be a problem. If I recall correctly there is a plug for the BLUE wire from the GEN bulb. Perhaps that plug is dirty or a wire is broken.
Thank you for your excellent presentations of your work on airhead BMWs. I have a 78 R100RS that I bought new and have done all the repairs and maintenance on it myself over all the years. The bike started leaking oil from under the transmission a couple years ago and it finally got bad enough that I decided to take out the trans and clutch to find the cause. All indications are that the oil leak was because the 4 screws that hold the oil pump cover had all come loose, with two coming out by hand and the other two only needing 1 or 2 in-lb to loosen. But while I am in there I am thinking I should also replace the rear crank main seal. However, I have tried to contact Cycle Works, based on your recommendation, to see if they still have the rear main seal puller/installer tool that you recommended, but I cannot get any reply from them either by phone, email or by using “contact us” on their website. Sorry to trouble you about this, but do you know if Cycle Works is still in business and still has that tool available? Also, since the main seal does not appear to be leaking, do you think I should replace it or leave it alone? Many thanks for your help, Jerry
Cycle Works is still in business as far as I know. They list the rear main seal tool on their website, so it’s available. You can order on-line. The owner is a one-man shop who also has a full time job, so he often does not reply to email requests, but he will fulfill orders for tools.
If the front engine seal is not leaking, I’d leave it be for the time being.
I’ve been following the S/T rebuild with very specific interest as I’m currently going through my ‘83 S/T. While having the bodywork painted I’ve pulled the swing arm and transmission to check and service the spines and the swing arm bearings. While I have the battery box out I’d like to paint it as well as the exhaust heat shield and rear rack. I’d like to use the Dupli-Color paint you used but can’t use an oven to cure the paint. Do you have a recommendation for other paints to use? The exhaust shield is a different color than the battery cover so do you use a gloss on items like the battery box, air intact and a matte on the exhaust shield? Other parts are the mirrors which I’m guessing those can’t be put in an oven? I’d like to get everything powder coated but I’m thinking with enough prep I can get a good finish using spray cans and powder coating gets expensive! I’m also thinking the brand of spray paint is important.
Great work on all of your projects! But more so your thoroughness of the processes, clear videos and extremely solid explanations which allow me to see and understand easily…..which isn’t easy! First time caller, long time listener, I refer to various posts constantly for reference. Thank You!
You don’t have to bake the caliper paint if you don’t want to. My exhaust shield is new so I didn’t have to paint it. I suspect you can use paint’s other than caliper paints for mirror’s.
I hope this helps.
Brook, after successfully repairing the power generating issue on my R100RS, I now have a “brake failure” light flashing on the dash when I rev it up (blip it). Not being a BMW guy, is this common and what would you think it be? I’ll check the master cylinder reservoirs for fluid but beyond that, what does this light actually mean? OK, off to check those reservoirs. Many thanks for everything, Price
Hmmm. It suggests a loose wire or connection as this behavior seems to occur with vibration. I suppose the brake fluid cover plunger which measures the amount of fluid in the reservoir could be sticking at a low level for some reason which would close the low fluid level switch in the cover.
Brook, found the issue and have fixed it. Seems that along the way the rear brake reservoir cap/float assy. had either been misassembled or most likely messed with by someone along the way. Once I took it apart, reassembled it a tad bit differently, it all works perfectly now. Full O fluid, no light. Low fluid, bright light! All the best, Price
Cool beans. Glad you got the problem sorted out.