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

Thread the needle, shoot the gap

Remember those small puzzles as a kid, where two loops of steel were wrapped around each other and you had to figure out how to detach them with just the right number of steps and angles and twist and turns? Like that, but heavier.

IMG_20171213_182351.jpg
That swing ain't for kids, either.

IMG_20171213_180802.jpg
Took a few cups of teas and good long look at the set-up to finally realize (and after checking this forum) that the transmission had to come off if I wanted to get the engine out of the frame. Or is it getting the frame out of the engine? Either way, just four bolts and the transmission popped off.

IMG_20171213_185023.jpg
I figure a pro (and/or any of you guys) could have had everything off and the frame ready for paint in what, four hours? I spent…17. Took it slow, took my time, figured things out as I went. Plus 700 photos, 100 labels and some very creative storage solutions in our over-crowded garage.
 
I am excited to keep following this build. I think you beat me to this bike by a day. If it is the same one I think it is you got s great deal.
 
I am excited to keep following this build. I think you beat me to this bike by a day. If it is the same one I think it is you got s great deal.
You in YVR and saw it on Craigslist for a few weeks, too? And it had terrible photos but turns out in person it was decent? But your buddy saw it first and bought it and now you're helping him rebuild the thing in your garage even though it's his and not yours and you wish you'd beaten him to the buying punch?
 
Yup YVR. Is it the one that "smoked a little after start up"? I hesitated and missed out, I may have to come by to check out your build sometime.
 
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Yup YVR. Is it the one that "smoked a little after start up"? I hesitated and missed out, I may have to come by to check out your build sometime.

Hah, it did, a bit (although I never saw the Craigslist ad myself)—mainly because a few seals are toast and there was/is engine oil weeping onto the exhaust / garage floor spill mat.
 
The 10,000lb elephant in the room

Did I mention we're powder coating the frame, so we'd like to have the drive shaft out of the swing arm, but I couldn't get the end nut—which is recessed inside the drive collar—off?

Took it to my buddy's automotive garage where a vibrating Snap-on tool (looks like a 1950s little ray gun), followed by an impact gun, got it off. Not easy, but not bad: about 15 minutes of contemplating and actual elbow grease.

The pressfit part…much harder. All sorts of pounding and vice-holding and blowtorching wouldn't budge it. However a 10,000lb half bearing press, plus some blow torch heat did, barely, and with a bang when it did finally release.

25440925_10159805565420525_1890065046_o.jpg
Beyond me, and almost beyond my buddy's tool.

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Seems strange that the press-fit is round-to-round (even if conical) for something applying large amounts of torque on the same plane…but I guess when it's 10,000lbs to get it to release, sure.

25435503_10159805641165525_907716203_o.jpg
A liberating sight.
 
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The key to the issue

Questions for tonight:
  1. Sourcing new seat lock?
  2. Options for matching keys / getting new keys?
  3. Sourcing new bolt and nut hardware…maybe ALL the bolts?
  4. Can you tell me more about this amazing frame pump the bike came with?!
Just an hour in the garage tonight, final prep on the frame before paint next week. Part of the side of the metal box around the seat lock came off when I unscrewed it. Must have been dinged at some point in the past—it just crumbled. Not essential but maybe I can source a new one. Although I'm still having trouble getting the steering lock off the frame. Actually, one more question: should I just grind that rivet out off from the steering lock cover?

As for keys, the previous owner only supplied us with one, and it's puny and looks like a copy (no rubber or plastic or BMW branding, I don't think), and it doesn't seem to work in the steering tumbler (it goes in, but doesn't turn it…I'll have to check if it works on the seat lock). I'm assuming keys are similar to Honda, where I can just bring the numerical code into a dealer and they can still get original keys for me.

Took a bunch of the footpeg hardware for a bath in the Simple Green Ultrasonic and they came out…well they're pretty rusted still. Looking into re-zincing them or just…buying new?

But what I really care about is this amazing frame pump we found in what appears to be a dedicated frame pump mounting area under the seat on the subframe and hell yes I'm overhauling it and getting it re-powder coated and (hopefully) filled out with new rubber seals. Coming to motorbikes as I did from a cycling background this is extra special and I will go to great lengths to ensure this pump is a show piece in this restomod (even if it never sees the light of day under the seat and would take what, five hours and arms like Arnold to pump a tire with).

IMG_20171216_192333.jpg
We may not even need a stock seat lock, depending on what we go with for a final subframe and seat.

IMG_20171216_193745.jpg
An ultrasonic cleaner and Simple Green can't work miracles.

IMG_20171216_200343.jpg
The pièce de résistance: the little (BMW?) pump.
 
Ooo, no kidding. I notice two things off the bat: the pin striping on the tank, and the grab bar on the seat—both of those original and stock? I know mine was repainted by the previous owner, and my seat doesn't have that grab bar.

I was willed this bike by a buddy of mine, who has since passed away. Can't confirm this is the oem paint and stripes. I think the seat is a replacement. I noticed your bike has a kickstart and aluminum turn signal housing. These bikes have some age and previous owners do their own mods.
 
As far as the pump, I would clean it up, refurbish it as far as the look to keep for bike shows. I've bought modern pumps that kinda replicate the oem pump and fits the frame mount and they work a little better than the original pump. Carry modern air pump kit if you are going to take care of flats on the road. Yes, I have refurbished a few oem pumps just for show.
In the past, I've changed out a lot of nut, bolt, washer hardware. Some from BMW dealers and some from hardware stores. I've also bought a lot of SS hardware as well, sometimes in one's and two's; sometimes whole kits specific to that motorcycle model.
If the whole seat lock kit is available through your dealer, that's probable your best bet. Most used ones are used up.
I've been through several total airhead resto's, rehab's, upgrades, etc. It's endless.
Ps I've also taken all the old nut and bolts hardware etc. to aircraft shops and had them cleaned and recoated. Worked pretty good.
Keep up the good work.
 
Did I mention we're powder coating the frame, so we'd like to have the drive shaft out of the swing arm, but I couldn't get the end nut—which is recessed inside the drive collar—off?

Took it to my buddy's automotive garage where a vibrating Snap-on tool (looks like a 1950s little ray gun), followed by an impact gun, got it off. Not easy, but not bad: about 15 minutes of contemplating and actual elbow grease.

The pressfit part…much harder. All sorts of pounding and vice-holding and blowtorching wouldn't budge it. However a 10,000lb half bearing press, plus some blow torch heat did, barely, and with a bang when it did finally release.

Hi Wynk,

I found this went easily with the tools from Cycle Works for this job. Here is my documentation on removing and installing the drive shaft with those tools.

--> 33 BMW 1977 R100RS Remove Drive Shaft & Swing Arm Bearings

--> 33 BMW 1977 R100RS Install Drive Shaft & Swing Arm Bearings

The press fit is commonly used by BMW for connections that transmit a lot of force. The interference fit almost creates a weld between the parts. To loosen is often easiest when you shock load the parts. A sharp wack with a rubber or leather mallet typically frees them. YMMV.

Hope this helps.

Best.
Brook Reams.
 
I found this went easily with the tools from Cycle Works for this job.

I have a feeling Cycle Works is going to take a lot of our money…holding out as long as we can. That said I've spent more time reading your rebuild blog(s) than I do this forum—your site's the go-to for what, every job on an airhead?
 
Two is better than four

Having overhauled the carbs on my four cylinder '78 Kawi half a dozen times, what a joy to only have two to tear down and rebuild. And I don't even have to break a sweat, swear, and scrape my knuckles pulling them out.

Took apart the right carb, seems straightforward so far. Every thing I could unscrew, I did, and then gave it all the 1-2 Simple Green + Ultrasonic punch, while noting what rubbers and gaskets need replacing (most of them). Took off so much gunk that parts I thought were steel turn out to be brass (i.e. the choke "dial").

The question now is: which rebuild kit to get:
The basic one from Bing (Gasket Kit #1),
Or the deluxe one (which includes new slides, and head & airbox rubber sleeves) from Bob's BMW (specific to 1978 R80 32mm Bings).

Needles and jets seem fine, float needles, too. Floats look alright, though one tab seems to have been tweaked a bit (previous owner?). I'll start everything off to factory spec on reassembly and problem solve from there at the final rebuild stage.

The sub-question is, how do my slides and diaphragms look? I need to read up how to get the diaphragms off, for starters, but quick inspection and they feel supple and intact. I'm debating with my buddy: I prefer to only replace parts that really need replacing. He's of the mind "Why take chances?" Especially when dealing with carbs, replace everything you can (if you have the money). My reasoning is mainly rooted in cost-savings, but partly in "don't mess with a good thing" and "solutions looking for problems often produce actual problems." On the other hand carbs have put me through a loop when problem-solving, so the less variables the better?

IMG_20171217_164601.jpg
The photo makes the slide look rougher than it feels?

IMG_20171217_164807.jpg
I assume this isn't the stock float tang angle.

IMG_20171217_191343.jpg
All the bits out of the washer. Definitely need new o-rings. The rest…well…not sure.
 
Given that you have flat top carbs and have no history on the carb parts, not to mention those floats look pretty bad, I'd say you need kit #7. The floats seem way to yellow/brown to me. Do they still even "float"? Snowbum has some info about what weights are associated with good and bad carbs. Another test is to drop the floats into a container of gasoline...if about 2/3 of the float is below the fuel level, then the floats are probably OK.

http://bmwmotorcycletech.info/bing-floats.htm
 
I'd say you need kit #7. The floats seem way to yellow/brown to me. Do they still even "float"?

That may explain the tangs being so bent (by previous owner(s)?) on my floats…to compensate for saturation weight. The fact the floats can get heavier, plus yes, not knowing the history of the carbs (although o-ring dust being a good indication I'm the first to think about sprucing these guys up since it left the factory) is enough to convince me to get the larger refurb kit from Bob's.
 
Re-coil

Alright, I've read a few threads on here and I still need clarification, and a recommendation:

What replacement coils to get?

My 1978 R80/7 with single plugs and a Dyna III ignition. Its original Bosch coils (Bosch part #0 221 100 022) look pretty rusted, on the outside at least, and I assume they're very, very old. A number of forums and and mechanic I work with recommend I replace them. But with what?

I want replacement spark plug wires, too. Considering making my own but maybe I should also order from Motorad Elektrik? And if the Dyna coils work, does that free up one side of my frame where the older, second Bosch-type coil was?

IMG_20171209_190025.jpg
One of the two original coils.

browndc.jpg
Replacement Dyna orange (or do people also call it brown?)

boschnew.jpg
Replacement stock Bosch "blue"
 
Carrying on

My membership's about to expire and didn't want to leave this thread dead-ended. Short story: my rebuild has started, most of the parts are in, think I understand how it's all going together. Follow along on my blog, everything for this build is tagged: http://jeffwerner.ca/tag/78bmwr80/

To answer my own question at the start of this thread, if I had to quickly think of the order of operations for this rebuild I’d work in the following order:
Sub frame on
Engine in
Fork and front wheel on
Final drive on swing arm
Final drive and swing arm in, rear wheel and brake, attach driveshaft to gearbox
Carbs on
Bench test full wiring
Controls and handlebars, cabling, lighting
Wiring harness (with intermittent tank- and seat-on tests)
Brake bleeding
Fenders and fairings

Here's a breakdown of the parts for the build:

Electrical
All new, simplified harness, with:
m.unit Blue and m.button (for data collection, built-in solid state fuses (remove relays), simplified wiring, customizable controls)
GXL wiring (solvent resistant, flexible but longer wearing than TXL) simplified to three colours, two gauges: red (power), green (switch signals), black (ground) and in 20AWG and 16AWG (and some 12AWG for direct battery connections)
Deutsch connectors, fully waterproof, compact, standardized throughout bike, less faults, corrosion
Dual wall (adhesive) heat shrink for weatherproofing all terminals
Split loom (adds modularity for removing / adding components, troubleshooting)
Voltage regulator (oem style, but slightly higher voltage, more compact)
12-cell LiFePo4 Antigravity-brand battery (compact, lightweight)
All new tin-coated and brass terminals for existing hardware connections
Grote LED headlight bulb and reflector, H4 plug-and-play
Hella 500 Fog lamp
7″ vintage style headlight bucket
Spark plugs and wires
Ignition coil (Dynatec 3ohm dual tower)
Posh-brand blinkers and tail light

Controls & touch points
Motogadget m.switches, 3-button (one on each side of the handlebar): momentary, most compatible with m.unit, minimal design
Vintage style dual-pull throttle,
Vintage-style cable-pull clutch and brake levers
Scrambler-style handlebars, to be drilled (for the m.switches and minimal aesthetic)
Custom seat upholstery (ostrich leather?) and foam on custom seat pan (by Crowe)
LED charging lamp indicator w/ custom bracket
Fog light toggle switch w/ custom bracket
Motogadget motoscope tiny with custom bracket
Footpeg and shift lever rubber
Tank emblems
Bar end mirrors
DIY length throttle and clutch cable kits

Engine
New valve seats (from leaded–>unleaded fuel)
All new seals
Deluxe carb kit
Filters (air and oil)
Cleaned and partially vapour blasted

Wheels
Powder coated black (including spokes)
New bearing in rear
New rim strips and inner tubes
New rubber (Continental TKC 80)

Frame, Brakes, Suspension
Still looking for a DR650 front fork
Custom front rotor, crowns, front fender, axle, steering adapater
Rear shocks (Ikon)
Powder coated black frame
Stainless and polished hardware throughout
New brake pads front and rear
Front master cylinder overhaul (may need the new piston kit), new stainless brake hose
 
That is a lot of time and new parts invested in the job. After all that and all the help you have received here, why in God's name would you be in a position that your "membership is about to expire"???? Do you really believe that when you have fitted all the parts back together the job will be over?

Friedle
 
Joined 12-1-2017, probably with the "Three-For-Free" trial membership. He'll put it all together tonight, fine tune tomorrow.
 
Hmm, I guess there's a lot of forums out there and I'm on a budget (this build is for a friend with deeper pockets). I'm not saying it's not worth $50 a year, but I am saying attitudes like the last two comments don't exactly entice fence sitters like me back. I was honestly considering the expense the last couple of days. I do appreciate everyone that put in a kind word to help, though, and I hope I put back as much as I got out of the forum.
 
I wasn't presenting attitude, just offering a possible explanation as to why a membership would expire so quickly. Probably could have included an cute emoji or two, but I didn't realize my sense of humor was so hard to "get".
 
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