BMW MOA such a great resource, thanks fellow riders!


Here’s a volley of discussion that I’ve been having on the BMW Motorcycle Owners of America site:

Would like to convert a wrecked 1977 R100RS to R1007

I’m just wondering how I can go about converting this bike that I think was originally a 100/7 and then at some point was converted to an RS, wrecked and now I would like to take it back to a /7. Everything is cool with that, but I can’t figure out how the wiring should work on it to get it back to a 7. If you’d like to follow my progress, I have a blog going at

-Ya gotta good resto going and it looks like you have a pretty good handle on getting to a finished product. Take your time and get it right, it will give you a chance to learn your bike with total hands on experience. I saw your pic sitting on the bike, it appears you would have been to big to sit behind a fairing. I’m looking forward to see how you progress.

-Thanks! I love riding and have a Suzuki 1985 GS 700 that I’ve been maintaining for the past 14 years. The electrical in the headlight of the BMW is a real surprise, but I get it. I’m just not sure that I have what I need to take it to a R/7 rather than an R/RS…I think I need to find a good salvage yard and pull a full harness off of an R/7…thanks for the feedback –


-the photos you show are of a /7 as you call it, ie the ign switch is installed in the head light ears which are also installed ,as these should not be installed if the bike had an rs fairing installed ? perhaps you have the models confused?


-I agree with the previous poster, I think you’ve got your models confused. If the bike looked like the one in the Butler and Smith advertisement it wasn’t an RS, that is an aftermarket Luftmiester fairing they slapped on. The ignition switch should be on the left headlight “ear”, it doubles as an attachment point for the headlight bucket.Yes there is a lot of wiring in the headlight shell. Fortunately it is color-coded at the fuse panel and there are plenty of resources to refer to if you get lost. Granted it has been many years since I ditched my old Lufty, but they used the same color wiring as BMW which helped simplify the process.

Good luck!

“…your body is not a temple, it’s an amusement park. Enjoy the ride” A. Bourdain
-If you do think you need a harness, you may want to consider getting a new one as opposed to a used one. It may save you some future headaches. I put a new harness on my ’77 R100RS due to multiple “no spark” and/or “no start” failures. Once we looked into the root cause, we found multiple spliced wires, bad connectors, etc. Replaced the harness with a new one, and I’ve been trouble free, at least from an electrical standpoint, since. As I recall, they’re not that expensive.
Brad D. – Member #105766
’77 R100RS – Black Beauty (big pipe, baby!)
’77 R100S – Ruby (S in RS clothing)
-yup, looks to be a standard /7 with a Lufty mounted on it.
-ign switch on an RS was in the cockpit area above the gauges (between voltmeter and clock), not on the headlight (which would have been fully inaccessible).
-those flat side brackets (visible in picture dsc 6958) are correct for a Luftmeister or Windcrammer, but most certainly not an RS.
-no sign of the RS “spider web” fairing bracketry (should have bolted to the steering tube)
-those handlebars would never have worked on an RS fairing.all that just means that you should have less extraneous wiring segments to deal with. the only differences between an RS and a std /7 would probably have just been a sub-harness for the volt/clock, adapters for the turn signals (maybe), and shorter lines to the handlebar controls. good news, less to do for you!


Ride Safe, Ride Lots
-Whats the vehicle ID number? That will help determine what it started out as. That might also match what it is now. The 77 78 R100S shared wiring harness with the 100/7, 750 and 600. The straight /7 touring bike had separate wire harness’s for the clock and volt meter where The S had one feeding both instruments. The RS has unique wiring for the fairing incorporated into the main wire loom.
-ign switch on an RS was in the cockpit area above the gauges (between voltmeter and clock), not on the headlight (which would have been fully inaccessible).I have a 75 R90/6 that I installed a RS fairing on and left the switch in the headlight bucket. It would be to much trouble to move to the cockpit area. There is no problem with access to it.Don


Originally Posted by bikerfish1100 View Post

-ign switch on an RS was in the cockpit area above the gauges (between voltmeter and clock), not on the headlight (which would have been fully inaccessible).I have a 75 R90/6 that I installed a RS fairing on and left the switch in the headlight bucket. It would be to much trouble to move to the cockpit area. There is no problem with access to it.


okay, forget the “inevitable”, and replace with “a wee bit annoying”. That about right?

Ride Safe, Ride Lots
-Thanks so much everyone, this is really helpful. Yeah, I was thinking that this was a 7 adjusted with the luftmeister fairing. The number on the frame is 6141650 R100/7, so this seems to hold with the idea that it is a 7 with a Luftmeister fairing. Thanks for that angle, I was confused, obviously! This is fun though, it’s like a mystery. Do you guys have a recommendation on where to get a new wiring harness? I would like to start fresh, or should I just run wires in from the turn signals and forget about the oil and voltmeter indicators? I guess I’m just confused about the relay set up if I run those things in independently…thanks a bunch for the input so far, it’s super helpful!

Very useful links for background on the BMW R series motorcycles

For wiring on BMW bikes, I’ve found several resources to be quite handy. On the ABC website there is a general color key for wiring on BMW bikes. See:

I like the large size color schematics from Prospero’s Garage. These schematics have a plastic coating so that greasy fingers don’t ruin the schematic. I obtained one of the schematics for each of my airhead BMW bikes. See:

Duane Ausherman has some good info on his website. See:

Rick Jones of Motorrad Elektric has lots of ‘lectrical stuff and his charging system book is very worthwhile. See:

A feller that goes by Snowbum has a lot of mostly text-based info on his website. This is a pretty useful resource. See:

Another feller, named Scot Marburger (aka Gunsmoke) has some very well illustrated technical articles on-line for airheads (more specifically the R100GS, but much is applicable to the /7). See:



So, when I went to put the wiring back together in the headlamp I realized that I have a slight problem. I think that this bike was originally a r100/7 that was converted to have the fairing and in that, made into a type of  r100rs…now I have to figure out how to take the RS wiring and get it to go to a /7 wiring. I will probably need to get an oil gauge and voltmeter. I could probably do without them, but what the heck. I also need to figure out the parking light and how to reroute wiring from the feeds that went to the fairing, which will now go more direct to the turn signals and gauges as well as moving the ignition back to the light bucket rather than wherever it was in the fairing…might have to moth ball this bike for a bit until I figure out a wiring strategy…

Starting photos and a current look at the bike


The day my Dad dropped the bike off. It’s got such cool lines without the seat.

Took a pretty bad hit to the front, destroyed the gauges, light, light housing, handle bars, front forks are yet to be determined as straight or not. I’m hoping they are, but we’ll see, I have a new set of used ones just in case, new boots too.

The seat and tail light with the rear turn signals was totally destroyed too. I have news ones of these to put on the bike now…

I have a lot to learn about this electrical system. Everything runs into the light housing. Thankfully I have marked everything after removal and have some great wiring schematics to base off of, it’s a real puzzle though…

Getting things removed and setting up new parts for replacement.

Truly amazing how much damage this bike took.


One of my work spaces…

Necessary information for the rebuild…complete with Star Wars blaster for my Boba Fett costume this halloween…

Wiring schematic with toe.

Getting into the nuts and bolts of it…

Petcock gummed up with ancient fuel…not too excited about what the carbs have inside them…

New gauges and handle bars installed. I love to see the old Wyoming license plate. The destroyed faring harness is above the battery in this photo. I think the faring is what preserved most of the bike in this accident. For my stripped down rebuild, I’ll be investing in some engine bar protectors in case it goes over again…


A starting point for a great bike


This is my forum for loading information about the path I will be on for whatever time it takes to bring a crashed 1977 BMW R100/RS7 back to life. This bike came from my Honors Literature professor in high school, Mr. Mork. I always enjoyed his classes and learned a lot. A common theme that always rings through my mind is the “storm without, storm within” concept. This concept in books and movies is that the storm outside of the characters is an indicator of the storm happening within them.

Mr. Mork wrecked this bike around 16 years ago in 1995 or so. It was a sliding accident on gravel and it put the bike in an end over end wreck. The wreck totally destroyed the gauges, light bucket and light, the seat and the rear tail lights. It looks like it took some impact on the right valve housing as well. As I take the bike apart I am amazed that Mr. Mork didn’t suffer more than a broken ankle. My Dad would run into Mr. Mork from time to time in Lander Wyoming and ended up buying the bike from him for $200. It sounded like it was a difficult parting for Mr. Mork, but he felt that if it went to me, then that would be alright. An interesting part of the story is that I don’t have the title yet and haven’t talked to Mr. Mork about the bike yet. I like the idea that this site may offer him some history on the process that will resurrect this very interesting machine. To date I have put around $1200 in parts into it.

Upon inspection yesterday I’m hoping that my carbs aren’t too gummed up, that the valve housings aren’t tweaked and that the front end is straight…I’ve been doing a lot of electrical work too since I’ll be taking this bike to a place where it won’t have the cowling that it did when it was wrecked. I like the more open look of the bike and am working it more to the R100/7 model rather than the R100/7RS.

I pulled a bunch of gunk out of the petcocks yesterday and drained most of the 16 year old fuel from the tank…the electronics in the headlight bowl are next….I can’t get this bike out of my head.