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Thread: 1978 R80/7 full teardown and rebuild…order of operations?

  1. #1
    Registered User wynk's Avatar
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    1978 R80/7 full teardown and rebuild…order of operations?

    TL;DR: Best practice and order of steps for a complete teardown to the bare frame, then building it back up again?

    Full story: I'm new to the Airhead world (have a few UJM motorcycles so far) and recently picked up my first: a '78 R80/7 with ~100,000 miles on it here in Vancouver, BC. Runs alright, bit of leaking and creaking here and there. Over the winter I'm doing a full tear down and restomod in my garage with help from a professional car mechanic friend, a Hayne's manual, and…you guys? I've spent about 20 hours reading up on the ins and outs of these machines. Lots of great forums and websites, from the Great List on here (https://forums.bmwmoa.org/showthread...es-with-Photos) to sites like http://w6rec.com/, http://www.motorcyclespecs.co.za/, and http://brook.reams.me/bmw-motorcyle-rebuilds/.

    So, where to start?
    What order of operations (airhead-specific or just general moto best practices) do people recommend to get down to the bare frame?
    What needs to be removed first so some other thing can get out?
    What are priorities?

    So far I've been going by these lists of airhead things to watch out for:
    http://www.flatracer.com/bmw-airhead-faq/4533419626
    http://www.motorcyclespecs.co.za/mod...r80-7%2077.htm

    Of note, we'll be:
    • Repainting the tank
    • Powdercoating the frame
    • Having the engine inspected / rebuilt by a local pro shop (Shail's for those in Vancouver)
    • Upgrading some electrical, lights, dials, li-ion battery (think Motogadget m-unit, etc.)
    • Fabricating custom luggage racks
    • Maybe a new(er), stiffer front fork
    • Getting the seat reupholstered

    Timeline is four months (I work part time); budget is…well let's start with best-case-sky's-the-limit and work down, down from there.

    IMG_20171201_235438.jpg
    The bike, untouched (by us) and straight from Craigslist last week.
    '77 R75/7. '78 R80/7 (restomod). '78 Kawasaki KZ650 C2. '82 Suzuki GS650G. '82 Yamaha XJ550 Seca.

  2. #2
    Registered User barryg's Avatar
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    First part of the disassembly is fairly easy, just grunt work. A lot of this is shown in the owners manual if you have one. Remove the side covers. Unhook the ground to the battery. Drain the gas outa the tank. Pull the fuel line off the tank, then remove the threaded nuts that hold the tank down. Off with the tank. Oem seats are held in by two pins on the frame. Slide the seat back and forth until the seat separates from the frame. It's tight but the hinge should just clear the subframe. Unscrew the nuts off the battery tie down, then remove the battery strap. Remove the nuts and bolts that hold the top of there battery box. This should let the battery box to tilt back. The battery should now clear the frame. Unscrew the the three nuts that hold the battery box to the frame, pull the batt. box out. Not bad for an hours worth of work. Take a short break, admire your deconstruction and get ready for the next step.

  3. #3
    Registered User barryg's Avatar
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    Oh, I see you got Krausers bag mounts. Probably best to unbolt that assembly first. Sorry, my bad.

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    Registered User wynk's Avatar
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    Quote Originally Posted by barryg View Post
    Oh, I see you got Krausers bag mounts. Probably best to unbolt that assembly first. Sorry, my bad.
    Good eye on the Krausers mount. That's actually the only thing I've done so far, last night. I've left, however, two ~3" metal plate adapters at the junction with the top of the rear shocks…they appear (I think?) to require removing the entire bolt assembly (and thus the top of the suspension to get them off), and I didn't want to risk having a one-person struggle to get the shock back in place. Figure I'll leave the wheels on as long as possible to aid in removal of parts (the bike's currently resting on the wheels in a dedicated motorcycle scissor lift stand).
    '77 R75/7. '78 R80/7 (restomod). '78 Kawasaki KZ650 C2. '82 Suzuki GS650G. '82 Yamaha XJ550 Seca.

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    Registered User wynk's Avatar
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    Quote Originally Posted by barryg View Post
    Oem seats are held in by two pins on the frame. Slide the seat back and forth until the seat separates from the frame. It's tight but the hinge should just clear the subframe.
    Mine was a bit easier—appears the seat pins are long gone. The two hook-like hinges were just hooked around the frame with no other measure to secure the seat except the plunger-like pin that locked into the left side mechanism.

    IMG_20171124_191237.jpg
    View under seat while on bike, forward-most "hinge" set loosely around frame

    IMG_20171201_151425.jpg
    Underside of seat "hinges". That's all there is, both on the seat and the frame.
    '77 R75/7. '78 R80/7 (restomod). '78 Kawasaki KZ650 C2. '82 Suzuki GS650G. '82 Yamaha XJ550 Seca.

  6. #6
    Registered User barryg's Avatar
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    I've gotta thread that's been put on hold. Lack of funds to push the job forward. It's called Classic Bavarian Bagger, a 74 R90/6. It's got some pretty good pics of deconstruction. This bike is slightly modified, but for the most part is stock. I'll try to bring it up to current page 1 of Airheads. Let's see if I can do it.

  7. #7
    Airmarshal-IL James.A's Avatar
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    You have a nice bike to start out on your project. I would suggest that you look over other epic rebuild threads for insights. There are at least two documentaries posted here by Brook Reams. Very thorough work well documented.

    There is one on Adventure Rider written by a good friend of mine for a 1974 R90/6. He sometimes posts here also. His screen name is fxray, and his ADV thread is called "My Barn Twins" in Old's Cool under the airheads sub-section.

    If you are a new or returning airhead owner, please consider joining the Airheads Beemer Club (ABC) When you get your first copy of the publication "Airmail", inside the back page is the list of Airmarshals by state or province. The Airmarshal should be able to put you in touch with knowledgeable enthusiasts to provide pointers.
    1973 R75/5

  8. #8
    Registered User barryg's Avatar
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    10-4. Instead of me bringing the thread up to current page 1 of the Airheads. Just do a web search. Classic Bavarian Bagger. It should come up and you should be able to to read the thread and see the pics. If there is any problem, just let me know and I'll bring it up to the current page 1 of Airheads. It's pretty much complete deconstruction to bare metal frame. I think you'll find it interesting. Your shop looks pretty good, you probably know your way around motorcycles in general. I've got all the shop books on BMW Airheads and most of the specialty books related airhead servic, maintenance, and resto's. I'm fortunate, I've got plenty of back up to help me. If there is a problem on finding the thread, I'll bring it up to page 1. Barry.

  9. #9
    Day Dreaming ... happy wanderer's Avatar
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    Howdy Wynk and welcome to the forum. The R80/7 is a great machine and it's great to see another one being refurbished. I own and wrench a couple of airheads and live in Vancouver. As past president of the BeeCeeBeemers MC club of BC I have some good Airhead contacts. If I can be of assistance just PM me and I will try to help out if I can.

    This past summer I prepared two R100RS bikes for a ride out to Harleysville PA for the 40th R100RS anniversary rally. My own bike was partially disassembled to repaint everything including the tank and re foaming the seat. The best advice I can give right now is to take pictures of every single thing you remove from the bike from a few angles. It gets hard to stay disciplined on this as I tend to get on a roll and forget to keep taking photos but when the project drags on (and it will....) those photos become invaluable when the time comes to put it all back together. You don't have a fairing to contend with but it's still a lot of parts.

    That R80 engine is one of the best things BMW ever made IMO and you will love it once she's all sorted out.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  10. #10
    Rally Rat 1074's Avatar
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    disassembly

    Since you've already been advised on the preliminary part removal, I'd like to mention my method. It's just the way that I do it and others will do it the same or differently.
    Keep in mind that when on the center stand and with weight removed from the rear, the bike will rest on the stand and the front wheel.
    Pull back the driveshaft boot and remove the bolts to the output shaft flange using the rear brake to keep the driveshaft from spinning.
    Remove the rear light assembly, then the rear fender. Move the rear wiring to the front and remove the rear fender.
    Remove the rear wheel and drain all fluids from the rear drive, driveshaft and transmission. Might as well drain the engine oil as well. Remove the rear brake lever and rod.
    Remove the rear drive and the right shock. Leave the left shock attached to hold it all up. Remove the swing arm pivots and then the left shock to pull the swing arm out.
    Remove the clutch actuating arm from the transmission, the carbs and air box that holds the air filter. Then pull the transmission.
    Remove the complete exhaust and all wiring going to the engine, coils and all wiring and electrical stuff attached to the frame.
    Get some help and remove the engine mount bolts and get the engine out of the frame.
    Pull all the wiring up to the front. Drain the brake fluid remove the brake hydraulic line starting from the bottom and remove the master cylinder.
    Remove the side stand. Pull the instrument cluster and headlight assembly taking the handlebar electrics with the headlight. Remove all cables and grips and get the handlebar lever assemblies off. Easier to do with the handlebar attached to the forks IMHO.
    Now you should have the bare frame on the center stand with the forks attached. Put the frame section onto a bench. I use a tie down strap to hold the rear of the sub frame down to get the front wheel off the floor and remove the front wheel and fender. Then take the top fork plate off, drain the forks and remove them one by one. Take off the steering dampener if attached. Pull the headlight, mounting ears and turn signal brackets and remove the fork stem and lower clamp. Then take off the rear sub frame and center stand. If I missed anything then look at the whole bike and take off what's left (horn?) at any point where it wont affect the balance of the bike or let it flop over.
    Of course, you've bagged and labeled all the hardware so that you can categorize everything before sending it all out for plating. You might want to take a bunch of pictures in sequence so that you can put it all back together in reverse order.
    Boxerbruce

  11. #11
    Registered User wynk's Avatar
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    disassembly: good process, baring any other tips I'll start with your steps and proceed.
    disassembly, happy wanderer: probably the no.1 piece of advice, which I've (we've all, I'm guessing) learned the hard way. Even when I think I've taken a lot of photos, I take more, from multiple angles. Has proven invaluable on other (minor) rebuilds and repairs. Doing this one proper, too, with a tripod and camera on a 60-second timelapse shutter, plus my phone for up-close angles. Have an assortment of clear baggies, rubbermaid bins, masking tape, sharpies and even hang tags to label everything (also share the garage with two other moto friends, so space is at a premium). It's easy when you put things back together next week—surprisingly harder after a month or three.
    '77 R75/7. '78 R80/7 (restomod). '78 Kawasaki KZ650 C2. '82 Suzuki GS650G. '82 Yamaha XJ550 Seca.

  12. #12
    Fortis Fortuna Adiuvat Omega Man's Avatar
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    Quote Originally Posted by barryg View Post
    I've gotta thread that's been put on hold. Lack of funds to push the job forward. It's called Classic Bavarian Bagger, a 74 R90/6. It's got some pretty good pics of deconstruction. This bike is slightly modified, but for the most part is stock. I'll try to bring it up to current page 1 of Airheads. Let's see if I can do it.
    Here is is- https://forums.bmwmoa.org/showthread...avarian-Bagger
    OM
    "You can do good or you can do well. Sooner or later they make you choose." MI5
    Mod Squad
    2009 F800GS 1994 TW200

  13. #13
    Day Dreaming ... happy wanderer's Avatar
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    Quote Originally Posted by wynk View Post
    disassembly: good process, baring any other tips I'll start with your steps and proceed.
    disassembly, happy wanderer: probably the no.1 piece of advice, which I've (we've all, I'm guessing) learned the hard way. Even when I think I've taken a lot of photos, I take more, from multiple angles. Has proven invaluable on other (minor) rebuilds and repairs. Doing this one proper, too, with a tripod and camera on a 60-second timelapse shutter, plus my phone for up-close angles. Have an assortment of clear baggies, rubbermaid bins, masking tape, sharpies and even hang tags to label everything (also share the garage with two other moto friends, so space is at a premium). It's easy when you put things back together next week—surprisingly harder after a month or three.
    Sounds awesome. For nuts, bolts and small bits I get used muffin baking pans and mark masking tape strips with what's in each hole. Cheap and effective for seeing what you have at a glance. Just don't leave it where it can be knocked over... DAMHIK!

    I did notice the quality of the seat pan shots. Just what you need. You will be finding a lot more rust on the foam side once you take that one apart. Seidenrock is now making some high quality foam replacements and whole seats if need be.
    http://www.siebenrock.com/en/product...ter.html?ac=44
    Another option is Capital Cycle. http://www.capitalcycle.com/search.a...t+foam&search=

    Or local upholsterers but the best ones are gone now. The guy at Main and 12th shut down (he was the best) and ASC on Knight St moved to Langley but no one answers the phone yet. I used a guy in Pt Moody and not that happy with the outcome after sitting on it for a 12,000+ kms ride out east in September so I would not recommend him.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  14. #14
    Registered User wynk's Avatar
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    Quote Originally Posted by happy wanderer View Post
    Or local upholsterers but the best ones are gone now.
    Yeah, we were considering seeing what the kids at Old Fashion Standards here in YVR might come up with, but instead sending the seat pan south and going with Portland-based https://www.newchurchmoto.com/ (I think it was New Church…buddy is arranging that end of it). I'm thinking we'll have to consider a new seat pan—shame to spend $300 on the reupholstery on a pan that'll just crack with rust in another year.
    As for little parts bins, I've spilled enough muffin tins…these days I put current bolts I'm taking off in a magnetic tray, then transfer to a ziplock baggy with a masking-tape label.
    '77 R75/7. '78 R80/7 (restomod). '78 Kawasaki KZ650 C2. '82 Suzuki GS650G. '82 Yamaha XJ550 Seca.

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    Registered User wynk's Avatar
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    Step One: tackle the easier take-offs

    Thinking I'll continue this thread with updates on my process in the hopes that the wise and experienced amongst us can continue to point out tips / problems. I'll also endeavour to search out answers from previous threads before asking here.

    I was solo flying tonight and spent seven hours stripping down, bagging, and tagging. Looked at recommended orders of procedure, as well as what I could accomplish alone and not screw up too much until my more experienced mechanic buddy's back from the weekend, and here's what I got through (text in bold is "next time armed with more knowledge before screwing it up"):
    1. Photo document full bike, and details= shots, from multiple angles (and photodoc every part before / after take-off)
    2. Seat off (wasn't bolted in at hinges, just hooked and resting on frame)
    3. Undo negative battery terminal
    4. Side fairings off (one rubber band), and bicycle pump from frame pegs.
    5. Tank off (two plastic thumb screws, hose clamps on fuel hose both sides) and drain it with petcock on reserve.
    6. Rear fender off (4x 10mm nuts I think, with bolt and plate falling out on reverse) with flap and rear lights still attached (unhooking single plastic connecter from main wire harness)
    7. Grab bar unbolt (13mm, and 6mm hex…more room to remove…)
    8. Battery out (plastic thumb screw and 10mm bolt to remove golding plate, tilt back in holder, pull up, turn 90º, curse, finally pull up and out between frame members). Holder rusted in (next time).
    9. Right passenger peg off
    10. Speedo tach single unit off: turns out electrical connector (10-pin I think) just pulls out, after I unscrewed backing plate because it was sticking). Single tach (speed?) cable unscrewed.
    11. Carbs (Bing brand) off. Slack off barrel adjusters, remove throttle cables first, undo intake and outtake clamps (stamped with BMW, nice), then undo choke wire with 7mm wrench…and here I thought I'd never use a 7mm in my lifetime. Head boots wouldn't come off easy, pretty dry and cracked, left on for now.

    Snack time: off-brand nutella jar warmed in water bath, eaten on a spoon, instant coffee.

    1. Right foot peg (19mm). Left footpeg…gotta read up on this first, as it's attached to shifter.
    2. Bleed out front brake (it's a later model with reservoir at the lever). Remove throttle assembly from bar. Removing calliper from fork seemed…I need to read more.
    3. Front fender attempt to remove…couldn't budge two bolts, nor flex fender mount off.
    4. Headlight bucket open (just one screw), unplug, unplug blinkers (after carefully tagging wire with location on board)
    5. Clutch lever off after slacking cable adjuster and pulling cable out from holder (surprisingly easy!). One Granturismo Italian grip was X-acto'd off in the process, though.
    6. Rear brake switch—had to unbolt the wires to pull through the frame.
    7. Choke off (one flathead screw)
    8. Ignition coils off (sounds so easy, but spent my time here to document and tag every connector).
    9. Headlight bucket off, pull out with main harness, disconnecting bare minimum. Wire harness from engine still on bike.

    Dinner: hotplate fry-up of some dumplings from the freezer.

    227 Photos taken. Here's a few:

    IMG_20171209_141541.jpg
    Status when I started at 2PM, bike complete.

    IMG_20171209_205348.jpg
    Status when I finished at 9PM: Central nervous system, brain, stomach, some small organs removed.

    IMG_20171209_212541.jpg
    Bike in a box (well, half a bike, in a few boxes).

    Full photo set (so far): https://photos.app.goo.gl/NWnCaikDAlUkulCG3
    Last edited by wynk; 12-10-2017 at 08:37 AM. Reason: Add photo album link
    '77 R75/7. '78 R80/7 (restomod). '78 Kawasaki KZ650 C2. '82 Suzuki GS650G. '82 Yamaha XJ550 Seca.

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