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1982 R80G/S

1982 R80G/S Paris-Dakar BMW Motorcycle Rebuild Project

Logbook of the rebuild

I scanned the internet on the various pieces of information that people have collected over the years about the early BMW Dual Sports, dubbed

"G"elaende (Terrain) /slash/ "S"trasse (Street)

There are many sources for information on the G/Ss and GSs, so I won't go into that. Here are a few that inspired me: I have been inspired by many bikes, (see pictures here). Here are two of my favorite:

My initial plan is to build a frankenbike. It is going to be my rider, so who cares! I have opted to build it on the basis of the monoloever suspension and swingarm for a very simple reason: it is the last driveshaft running in oil and has only one U-joint. There were many problems reported over the years on the paralever U-joint and its limited lifetime. Of course it can be repaired and improved, but at a cost. You don't hear much from the monolever community.
The project has a slow start and is expected to be long term. I am undecided whether to buy a complete bike or buy it in bits and pieces (which is really what I would like to do!). My focus right is on scanning the market and find either a R80ST or R80G/S (even a R80GS or R100GS) or a ST or G/S or GS frame.

November 6, 2005:
I had to rewrite the history of this project from here on. Previously I managed to acquire a couple of nice pieces, which, when put together, can be considered a rolling G/S chassis. Since then, I won the lotto! There is no other way to describe how I got to own a R80G/S, one of four (4) G/S manufactured in January 1982 for the North American market.

I do not know anything about the early history of that bike, and would appreciate any help: the VIN is 6362759 (it has the 17-digit VIN), and according to the Ontario Licensing Office, I will be the third owner. One of the previous owners (the first) was Charles Lapointe of Toronto, Ontario who registered the bike in September 1982. Looking at the oxydisation and current mileage (36.979km) the bike must have spent a considerable amount of time in one or more basements. I know the last (second) owner had it for 2 years and I think, he never rode it ... but I can't be sure. I guess you could describe its condition as "neglected" but not beat up at all. And it is hardly broken in, if the mileage is correct.

Well, the fact that it did come with the original Paris-Dakar tank, signed by Gaston Rahier, did sweeten the deal even more. However, the signature is already starting to fade and will disappear over time. Unless I find a way (painter!) to restore it. But if not, so be it! It is an original Paris-Dakar tank and it was signed, that's all that counts!
Both tanks are in the traditional Alpine White, Henna Red and Tuareg Blue. Last, but not least, original tool roll and GS Manual came with it as well.
So, what's the new plan? First I'd like to rework it mechanically so that it is rideable. It will then be my daily rider next year. It is my intention to do a full-blown cosmetic rework (Winter 2006/2007) once I have figured what the engine is like.
November 7, 2005:
The last two days I worked on the no. 1 issue: electrics had to be sorted first. Got a battery in and not unexpectedly, nothing worked. I spent a couple of hours with cleaning connections and plugging/unplugging connectors. Stupidly disassembled one of the handlebar switches and if I had not had a spring and one of these tiny little balls in reserve, I would have had to pay dearly for my stupidy. I was lucky, but lost valuable items such as the small spring and ball. I removed a ON/OFF switch for the headlight that had been installed in the back of the headlight "bucket" and instead, got the light relay back to work. This switches off the light automatically when the starter relay is activated, a "US only" modification as US bikes obviously have no ON/OFF switch as driving without lights is not permitted anyway. Electrics now working fine.
Alle cables, throttle, choke and clutch were cleaned and oiled. They were all rusty, but replacing will have to wait until the real restoration starts. I also loosened the exhaust nuts as I did not want them to get sticky. Didn't know when their were last removed, and it took heat and a good amount of WD40 to get them loose. I cleaned them up with a steel brush and will reassemble with good ol' copperpaste.

The carbs were completely refurbished when I got them. I checked the first and found an o-ring at the wrong spot on the idle jet. The idle mixture was not correctly set, so I went through both. Last but not least, I got a bit of Armour and started cleaning the plastic parts such as lamp and indicator housing.

I did some digging on the internet with regards to preserving that Gaston Rahier signature on the Paris-Dakar tank. Am talking to some airbrusher. Those guys know how to deal with it. Somebody has an idea, let me know.

November 8, 2005:
Only a couple of hours today, but enough to
  • put a battery in, which does not fit the tray (too wide, 4" instead of 3") but is as good as new, a leftover from an earlier project, fixed it to the battery tray with cable ties
  • put new fuel line in for the crossover
  • fitted the carbs, throttle/choke cables and air intakes
  • and called it a day

  • November 9, 2005:

    It's alive!

    Man, these bikes are light and have grunt! I rode a '78 R80/7 once and can see the difference now. It still runs rough, but no funny noises so far. Rear and front end feel if if there was no oil in the shocks/forks, front brakes need a good look at. Electrics is all fine, charging circuit needs a lookover as well, just in case. Tires are fine, so the necessary safety to get it insured and plated should be a walk through the park. Can't wait to go for a longer ride before the first snow.

    November 10, 2005:
  • finished replacing all fluids (semi-synthetic in engine and tranny for now)
  • removed the SLS system, bike runs better now
  • charging system not working, rotor and stator resistance are fine
  • rear shock is definitely shot, leaks oil

  • November 12, 2005:
  • charging system is back online, the alternator brushes were getting a bit short, that is why the GEN light was not sure whether "To DIM or not to DIM ...", solved it quickly by installing my spare 238W stator, the other one (280W) will be repaired and installed in the PD ... which again creates a spare 238W stator
  • attacked the forks today: after filling them yesterday they went rock solid, no movement
  • drained them (again): this time, after a bit of convincing (because I knew there was at least red oil in them) about 220ml of yellowish substance came out which could have been fork oil once and another 220ml of red fork oil, just like the one I put in yesterday! (my brain should have clicked when the fork overflew after 200ml yesterday ...!) -> the forks were completely filled with oil and just could not move.
  • the fork seals (8x36x46 double lip) were shot and the boots are gone too, so I disassembled the forks to check: heavy pitting in the top section, no harm for the seals though

  • 7 spots/areas of pitting on the lower section, which would definitely harm the seal, so JB Weld will help me out to fill (will post pictures when sanded and ready for action)

  • November 14, 2005:
    After two applications of JB Weld and wet 600/1200/2000grid sandpaper, the pits are filled and the surface perfectly smooth:

    November 27, 2005:
    Just two smaller, but effective modifications today (no pics): added #10 ground wire from timing chain cover/diode board ground to frame and from there to battery minus. That should deal with an grounding issues of the charging system. I furthermore did a very slick modification (courtesy of Dave Thompson of Champaign, IL), which sort of added a headlight switch to the bike without actually adding any hardware: just move the green wire (15) on the ignition switch to the grey wire (58). Result: in "park" position, the ignition is now switched on (front and rear parking lights are on as well), the bike can be started. In "on" position, the headlight comes on. As simple as that. See the whole procedure here. I really like this modification!
    December 11, 2005:
    In the long run, I would like to fit the GS front end I had specifically bought for that purpose. The steering head bearings look brandnew and both triple trees cleaned up nicely with no signs of damage. See a couple of pictures here. I will also use a set of straightened fork tubes from my PD accident bike.
    December 20, 2005:
    The parts for the forks (gaitors/seals) and the brake pads finally arrived, so I put her back together. The rear shock is still with Bruno for refurbishment. A piece of wood will do for now, the ride in the snow with this "fixed frame" was interesting.

    December 30, 2005:
    Time to get the old red seat cover replaced with a black NOS Hein Gericke seat cover, probably 20 yrs old, but in its original packaging, 12 bucks on ebay Germany. Can't beat that. It had a few imperfections from the long storage, but nothing serious.

    I had some experience form replacing a seat cover on a /5 seat and it helped me a lot with the "cement" job. All in all it went ok. The cover was not too well prepared at the back of the seat (no appropriate darts to get round the back without pleats) , so I had to come with my own idea: not too professional, but working. It also had a black rubber trim which I installed as well. See few picture here:

    January 04, 2006:
    You have heard this sort of slurping sound when you press your brake lever? Happened to me and made me look at the master cylinder: it must have sat a long time outside as there was significant pitting on the inner wall. I had a spare 13mm master cylinder which I cannibalized. Ordered the necessary rebuilt kit and had the mastercylinder refurbished with all new seals and piston.. The pitted 13mm body I will have reground to 15mm , buy a 15mm piston and use it for my planned dual brake setup.

    January 14, 2006:
    The bike is definitely a bad starter, takes quite while to get it going. Always the same: first kick ... one wroommm ... and dead again. From there on it takes 20 kicks plus the electric starter to get her going. Once she is warm, she idles ok and runs fine, no smoke. Valve clearance fine, carbs cleaned and default adjustment, ignition fine, spark fine. I kept wondering and one day I checked compression cold: 4-6 bar (using the kickstart). Not good enough. I looked at the seats of the valves throught the spark plug hole and they were not loking great I thought, somehow rusty not blank anyways. So I decided to get the whole kavoom off and check. First off, the barrel and head were very (very!) hard to separate ( had to use a lot of heat and WD40) as if the engine was never opened (37000km). There was not a lot of carbon residue, but rust in the valve springs, signs of water on the inside of the valve covers, I figured this engine sat for a long time and there was water building up, either through condensation or maybe even rain.

    Anyways, to my surprise, the left cylinder looked very good, no pitting on rockers or valve heads, the valves looked not too bad, the heads are not heavily recessed or anything, the seats seem to be slightly pitted on the valves, hence the low compression, the Nikasil barrel (marked 80) still show the honing marks, no signs of pitting due to water or rust, only a few vertical marks from the pistons, piston looks goods, has carbon build up and isw not yet cleaned. need to measure the rings but they look fine too. My favorite expert on valves and the likes recommended to grind the inlet valves, as its seat is slightly concave and also to regrind the exhaust valves as it is slightly recessed. The seats should then be reground to match. High Resolution pictures of left cylinder are here. Same applies probably for the right side: reground valves and match seats, maybe honing the cylinder to get rid of the piston marks? High Resolution pictures of right cylinder are here.
    January 22, 2006:
    The driveshaft boot is damaged on both ends! I am not thrilled with the idea of ripping the rear end apart, but whilst I am at it I might as well

    I hope this is not going to be a construction site for the next 2 months, but at least I have touched everything and know its condition.
    January 30, 2006:
    I had worked on the gearbox, cleaned it up, repaired the neutral switch which was stuck, checked on the seals which seem to be ok. Cleaned the clutch mechanism, replaced spring and clamp and got it back together. Plan is to have one ride to completely warm the oil up and add something to flush respectively clean the inside of the tranny, than change oil again, add Molyslip and be done with it for now. It shifts fine and should be ok without opening it. Judging from the rest of the bike, it should only be oil crud that needs washed out and the box should be as good as new.

    February 1, 2006:
    Got my heads and barrels back: all valves and seats reground and lapped, cylinder walls de-glaced (spelling?), looking really good and is ready for installation.

    See a couple of more pictures here.
    February 3, 2006:

    February 13, 2006:
    Cleaned and refurbished both petcocks with new fiber washer, o-ring and rubber seal. They were not leaking but the rubber might have been very old and upon using the bike more frequently, might develop a leak later. I had the parts leftover from an earlier restoration and just did it for piece of mind.

    February 18,2006:
    It was a beautiful day today and I thought it would be a good opportunity to try "The Emperor's New Clothes". See the results for yourself:

    March 05,2006:
    My speedo is busted: missing needle and reset knob rubber shot. Now, on tour I use a GPS that gives me all the info I need. But how about the rest of my riding, those Sunday afternoons? I still want to keep track of the mileage of the bike (bought it with 36979km) and I did not want to spend 100 bucks on a new BMW speedo just now. So, I did what other people had done before: I went to buy a SIGMA bycicle speedo (Model No. BC1200, a 2005 model) as I heard good things about them and it also seemed a pretty straight forward thing to do. I bought the wireless version, but it requires "line of sight". I was not sure whether to even try that and bought the additional Rear Wheel Kit from Sigma and fitted that instead. Used some silicone to afix the parts and will see how that works out over time.

    March 11, 2006:
    Today was the day: all system were GO, the bike safety'd, plated and insurred, the weather forecast was right: 10C warm/no rain ... it was time for the maiden trip.

    First, I broke the engine in: followed MotoMan's Break In Secrets and had a 30km run in the morning. Changed all fluids (engine/tranny/drive shaft/final drive) afterwards again with no surprises on the magnetic drain plugs. After lunch, I embarked on the maiden trip: wonderful weather, the 800cc engine was running sweet and so was the bike overall. Up until after about 2 hours ... I lost my gearbox. Out of nowhere, the only gear I could use was the first! Glad, I was only 10km from home. So I limped home on 1st gear. I had planned to open the gearbox anyways at some point anyways as the shifting was a bit strange on the morning run. Now that point of time has come early! I was not too disappointed (I expected Murphy to strike one way or another!), the bike was running very good. Upon coming home after 120km, I checked the compression: 135 PSI on the left and 135PSI on the right. I am delighted.

    Now, I will have Bruno take look at the tranny. Winter will be returning anyways and my first longer trip is not before end of May.

    March 24, 2006:
    Another perfect example for a JB Weld repair. The clutch pushrod was completely pitted where it was exposed to humidity for many years. If it wasn't for my stupidness I would have even got a "before" picture. But, I only have the "after:"

    October 12, 2006:
    Although the repair was perfectly "executed", the road- and lifetest of the repair can not be considered successful. I had the bike apart for the odd winter job and thought I'd better check and see how that repair held up. It didn't:

    The fine print on the JB Weld packaging does state that it is resistant to petrol, oil and battery acid. Mineral gearbox oil and motoroil should not be too much different so it maybe was the constant interaction with the seal that made it come loose. Also, the surface was probably not exactly clean (I only applied acetone to clean the surface), and the rust must have contained enough dirt/grime/particles to prevent adhesion of the JB Weld, combined with the thinness of the application ... it just didn't work out.
    March 25, 2006:
    Well, it was time to put everything back together: The bike is all back together and ready for the next test rides. I plan 2 more test rides of 200-300km before I can consider the bike fit to go "anywhere, anytime".
    March 26, 2006:
    It is done! The second test ride on a beautiful Sunday morning was such pleasure, I couldn't wipe the grin off my face:

    Still need to do some tweaking on the carb settings, she is running a bit lean. Other than that, I am planning the following modifications/additions in the near future: My restoration report sort of ends here. It will become the bike's logbook from here on.
    April 09, 2006:
    There is a first for everything! Today I had my first experience with the G/S on a trail-type side road with deep grooves from farm trucks and lots of water ...

    Needless to say, for an absolute NooB I did okay: dropped it only twice in about (what seemed to be) a mile, no damages, but plenty of grin on my face! I did it.
    April 30, 2006:
    I am in the final stages of preparing the bike for the upcoming trips in May: a 600mls weekend trip up to Bancroft in North Eastern Ontario and then later the month I am going down to Oklahoma to the Boxerworks Forum Rally May '06. First, my Dad made an spectacular deal with a Hepco & Becker Luggage Carrier, a very solid and well fabricated unit, see a couple pf close up pictures here.
    Secondly: I always wanted a voltmeter. Not that I don't trust my charging system, but I don't like breaking down. And although a quite simple and robust design, it's always good to know that it works! The BMW stock Voltmeters with the pod, although very nice, just don't want to fit into my budget right now. Instead I bought Joerg Hau's LED-type design which provides a simple GO - NOGO indication, see a detailed description on Joerg's website.
    Finally, I got my GS windshield. So far, I ran the bike without and got quite long arms. Having installed the windshield, it takes away quite a bit of pressure from the chest. Quite a while ago, I bought a K75C windshield. I fitted that on top of the GS windshield for additional protection and it works beautifully. The pressure is off the chest and my arms stay short.

    The bike is starting to get this distinct 'round-the-world-in-80-days look, don't you think?!?

    May 06, 2006:

    A couple of friends and myself went up North East to Bancroft, just for the ride and to visit another friend who lives up there. Besides having a good time with some nice folks, I also did the final test before The Boxerworks Rally on May 19-22. It was a full success! I had my lowered footpegs installed and they made a serious impact. The (shortened) ErgoMod gearshifter is absolutely brilliant, I thought I had a new gearbox.

    The only thing, that did not work out straight away is the footbrake: it is hard to get to with the lower footpeg. I will fabricate an extension made of aluminum, similar to the ones TT offers. That will take care of it. The other, sort of annoying thing is the fact that I can't use the kickstart anymore. The footpegs were designed for the '88 onwards GS and they had an optional kickstarter whilst it is stock with the 1981-1987 G/SD. Ah well, never mind, I bought a Panasonic Sealed Lead Acid Battery (LX-1220P) for C$68 delivered to the door at Digi-Key. You can't beat that. The K75C windscreen on top of the stock GS windshield does a marvellous job, no long arms or neckache or anything. Seems I am ready for the final check: valve play and new "summerly" motoroil.
    May 10, 2006:
    About 2hrs with some files, a dremel, a drill and some other handy tools led to this foot brake extension "a la ME":

    Now I'll find the footbrake again!
    May 24, 2006:
    My first big trip: Boxerworks Spring Rally May 2006 in Big Cedar, OK
    June 29, 2006:
    I was working a few weeks on my seat, adjusted my front forks and "creamed" my Paris-Dakar tank with POR15 so that I can use it. The seat became a bit of a soloseat now and I found a nice bright orange vynil cover to make it look nicer ;-) I installed the ToasterTan upper triple tree that I bought from him 2 months ago and used this opportunity to adjust the front forks. It was easy, but time consuming using Randy's instructions that Duane hosts here (unless he changed his website structure): Click on this link: http://www.w6rec.com/duane/bmw/fork/title.html. The tank took a bit longer, as I was following the instructions carefully and doubled penetration times were possible. I think it went well, but only time will tell. Here are a few pictures of the new look (without the black Alaskaleather sheepskin):

    July 18, 2006:
    The K75C windscreen was further supported to the handlebar with some ingenious screws I found. And finally, the RAM mount for the Garmin was installed.

    October 22, 2006:
    I did a two weeks trip down South to run part of the Transamerica Trail, Deal's Gap and the Blue Ridge Parkway. Overall, a 4179mls/6275km adventure that is described here.

    November 5, 2006:
    Back to Square One (was I not just there a couple of months ago?):

    Time to attend to those things that became evident during the trip: Final Drive:
    The final drive has maybe 0.5-1mm play between input and output. The oil looked very good, no solid pieces anywhere. I opened it up and here is what I saw:

    Another drive I opened showed a similar wearpattern (worn on the edge), but only 1/3 of the coverage. I spoke to my trusty machinist Bruno in Iron Bridge and he suggested shot bearings and pinion gear shimming needs. I have to agree, the bearing feels a bit tight, but hey what do I know. So, the final drive goes up North for a good lookover.

    April 2007:
    The temperatures are rising and it is time to put it all back together again: I had the carbs nicely synch'ed and the bike runs like a charm.
    May 2007:
    Some time ago I bought another original G/S seat to be used for another project. That project turned a different direction so I thought I use this seat to build a bench-type seat as opposed to the custom single seat I had been using so far:

    I went to the local Foam Store in Kitchener and they cut me some 1/2in thick 6.5lb/sqft density foam sheets which I applied in layers using spray-on glue.

    Bill from Gold Star Upholstery here Cambridge has done all my seats over the past 3 years and he did an excellent job on this one too:

    36in (914mm) seat height and yep, it had to be Dakar Orange. What else!

    June 2007:
    I can't get used to it: my front end still feels very stiff. Also, it is not well balanced with the rear stock shock. Changing the pre-load spacer did not change much in the feel. I ran about 5000km so far but I am not happy. I did some simple calculations and experiments with different springs which I have described here: Front Fork Spring Rate Comparison. Now, I am running a combination of Work Performance and stock G/S spring and am much happier:

    There is actually some softer damping action happening in the front now, but admittedly at the expense of a bit more diving. Not badly, not bottoming out, just a different feel to the harsh Works Spring performance. If I go and use a three-piece combination consisting of the Works shortened soft spring, the shortened G/S spring and the hard Works spring on top, I might arrive at an optimum solution, but I first want to try out what I have so far before I am cutting some more springs in half.

    October 2007:
    Trip report of my Grand Fall Ride 2007:

    The logbook ends here on November 17, 2007 when I sold the bike in close to stock configuration.

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