1977 R100/7 Project Bike - Intro and Questions

Hello,

A few months back I picked up a 1977 R100/7 as a project bike. I found it on Craigslist; it needs a lot of work but the price was right (or, not terrible at least), and I figured it would be a great learning experience. I'm at a point where I will start needing the collective wisdom of this forum, so I figured I'd start with an intro post.

Here is a brief background on me and the bike for those interested; questions will be at the bottom of this post and in later posts for those that want to skip ahead. I'll try my best to search here and elsewhere before posting questions.

I live in Northern Virginia, and also own a 2008 R1200GS I bought new. I've enjoyed doing my own work on it with the help of GSpot, the JVB DVDs, and the local BMW club tech days (BMW Bikers of Metro Washington). I was psyched to learn that advrider also had this Airheads forum! This is the first major project like this I've ever taken on. I do all the regular maintenance on my GS, and have installed some farkles. I've also done things like new radios and remote start installs on our other vehicles, and new struts, brake rotors/pads, lower ball joints, upper control arms on my Explorer. So, I'm pretty handy but don't have a whole lot of experience with this stuff, so I have to learn as I go.

I've been reading many of the helpful threads here, I've been in touch with Snowbum and have consulted many of his tech articles, I've signed up for the airheads mailing list, and I've purchased the Clymer manual. I'm also very fortunate to be pretty close to Bob's BMW and Capital Cycle. With the help of a friend/neighbor who has restored a few Porsches and VW Bugs, I've started tearing down the bike to get it running again and mechanically sound.

Here are some pics of the bike when I picked it up (carburetors were removed before these pics). In addition to that awful rear case, the bike came with two Krauser cases that are in very good shape. Unfortunately the brackets you see installed are not in as good of shape.



It has about 44,000 miles on it. I don't have much of the history of the bike, but from some of the decals it looks like it was in regular use up until 2001 or so. Unfortunately, the last owner became ill for a number of years and didn't do much with it, and then I purchased it from his daughter a few years after his death. So, the bike sat for a while, outside for at least part of that it seems. It turned over but didn't run when I purchased it; the tank was completely rusted on the inside, and both carbs and one of the heads indicate they had standing water in them for a period of time. The tires are shot, and the exhaust was completely rusted out. Inside of tank:



Yeah.

Thus far, the major things we have done:

- Removed rear case/ bracket, backrest, Krauser brackets, and Plexifairing 3 windshield
- Removed exhaust
- Sent the tank out for rust removal / sealing / priming (not back yet)
- Completely disassembled, cleaned, and rebuilt both carburetors
- Rebuilt both petcocks
- Sent the heads to Paul Sturges to have one of the exhaust threads rebuilt (that was a fun day ), new valve guides installed, valves reseated, and heads bead blasted (BTW, Paul does amazing work at a great price!)
- Pulled both cylinders, and bead blasted the outside of the cylinders, the valve covers, front engine cover, and oil pan
- Reinstalled oil pan with new gasket
- Removed steering damper (it was shot and leaking)
- Replaced choke cables

Pistons and interior of cylinders look good so far.

Carbs, petcocks, and heads:



Current state of project:



I'm still waiting on another shipment from Capital Cycle, and then our immediate plan is to get the motor, carburetors, new fuel lines, petcocks, and resealed tank installed. We are also going to rebuild the master cylinder and front caliper, replacing the brake line and the piston if necessary. First order of business after that will be replacing all the fluids/filters and then checking out the condition of the clutch, transmission, and final drive.

Long term plan for the bike is still up in the air at this point. Priority is to get it mechanically sound, and worry about cosmetics later. A few weeks after I purchased the bike, my wife and I found out she was pregnant with our first children (twins!), so I probably won't have as much time as I initially thought for the bike, but I'm really in no rush.

I'm thinking I would eventually like to restore it to a mostly stock look, with black paint and pinstripe, the only exceptions being Euro bars with bar end mirrors, and a different seat.

I don't plan on reinstalling the windshield or Krauser cases, so if anyone is interested, let me know.

Sorry for the long intro. If anyone has any general tips or suggestions based on the plan of attack I laid out, I'd be very happy and grateful to hear them. Also, if anyone in the NoVA area is interested in being an "Airhead Mentor" (we call them "Elmers" in the Ham radio world), I'm all ears!

First Questions:

1) When we pulled the jugs, there were no gaskets between the engine block and the jugs. There were no indents for the large o rings that some jugs have. Both upper cylinder studs (correct term?) on each side had small o rings around them, but that's it. It didn't even seem like sealant was used.

The Clymer manual indicates that a gasket should be there, and an o ring if there are indents for it. Snobum's tech article seems to indicate that sometimes neither large o rings nor gaskets were used, only high temp RTV.

When we reinstall the jugs, should we just use just the RTV and the small o rings on the upper studs, or should I get gaskets? If gaskets are used, do you forgo the RTV?

2) I've read a lot about the "$2,000 O Ring", and I'm still a bit confused. When I pulled the oil filter cover, it had a single gasket behind it, and the oil filter o ring was in good shape and looked like it was seated well. I'm going to replace it, but is it safe to assume I can just replace the o ring, install a new gasket behind the cover, and all will be well?

Thanks,
JDC

JDC! hello:)

IIRC...

1) - no base gasket, just the 2 small orings and some sealant (there are many opinions on which sealant) - just be sure not to clog the oil passageways.

2) it is not safe to assume that does snowbum have a long, wordy article about it? re-read it a few times OR find yourself some local airheads (I did). It is not complicated, but you want to be sure you have measured everything appropriately and add/subtract shims as required. the danger is not having correct oil pressure.

good luck!
spencer

Thanks! I'll take another look at Snowbum's article and break out the calipers for the oil filter cylinder measurements. Do you have a picture by chance of what the shims look like and where they go?

ETA: Nevermind, I found this: http://www.largiader.com/tech/filters/canister.html

My canister definitely has the sharp edge, and no shim was installed when I removed the filter. Where are these shims available?

If you need another source for info and parts try calling Hans Lowe at Hucky's BMW Parts. Google him up and get his phone number, talking to Hans is like having a direct connection to the " Factory ". He knows his stuff.

The shims come with the oil filter.

Oh and this is Shane I think I meet you at Ed's and I think Jim's

Shane

Hey Shane! You're the one with the Tiger right?

Thanks for the info. I don't think the filter I ordered from Capital Cycle came with a shim, but I'll check again. There definitely wasn't one in place when I removed the cover and the old filter/o ring.

John

It's good you found Anton Largiader's article on the oil canister. Snowbum has tremendous knowledge and experience, but his writing style is not what you'd call elegant. Fewer words and more pictures and diagrams would be helpful.

Measure the depth from the top of the filter canister to the flange where the filter cover plate sits (where the paper gasket was). It should be somewhere around 4mm. The idea is to compress that white O-ring a bit. The O-ring is nominally 4mm thick, but it can't hurt to check the actual thickness.

If your canister has a sharp edge, at least one shim is required. Sometimes two shims are called for, if you measure the depth greater than is typical. The shims are about .3mm thick. If the depth is small, you may need the paper gasket (to prevent the O-ring from getting squished too much). As I understand it, the paper gasket is usually NOT needed.

I think the shim (sometimes called a ring or washer) is part number 11-42-1-336-895. It should be in stock at any good BMW dealer. Maybe you're like me and don't live near a good BMW dealer? I order stuff from either A&S BMW in California or Max BMW in Hew Hampshire.

The white O-ring--the larger of the two--is the critical one. It keeps oil from bypassing all the bearings and going straight from the pump back to the crankcase.

The slightly smaller black O-ring is important, but not critical. It keeps oil from bypassing the filter.

EDIT: My R-100GS PD has the two O-rings, one black and one white, because there's an oil cooler whose lines attach at the cover plate. I'm not sure the set-up on your /7 will be the same. If it differs in this area, please disregard everything I've just written--except the part about the white O-ring and dimensions of the spot where it lives. This still applies.

There's also a small O-ring (like small enough to just fit over your finger, maybe) that goes on the bottom of the filter element. The filter usually comes with it attached. Sometimes it gets detached and stays on the little tube at the bottom of the canister when you remvove the old element. If that happens, you want to reach in there with something and remove it, because having two in there at once is not a good thing.

I can't help you with cylinder base gaskets and O-rings, other than to say, "good luck," and it looks like you have a fun project there.

Thanks for the info on the shim and the measurements. My bike doesn't have an oil cooler, just the indented oil filter cover with no connections coming out of it.

The filter I bought came with two of the smaller "finger" sized gaskets you mentioned; they almost look like miniature radiator hoses about 1 cm in diameter and length, and the filter I removed had one on each side as well. I understand the function of this gasket on the inboard side of the filter, but does the outboard one get installed as well if there is no oil cooler? I'm assuming that it somehow keeps the dirty oil that's coming from the outside into the filter going in the correct direction (inboard) versus coming outward toward the oil filter cover?

Just to add to the work plan:

I would add, remove and regrease both sets of wheel bearings and the swing arm bearings. It also likely that the headstock bearings should be cleaned and regressed. When you are doing this you will see if any of the bearings need replacement, this is all good stuff for a stable bike. These old bikes have rather more stability issues than your modern GS!

Charles

Hi there - I just picked up a 77 R100/7. Wow man, overwhelming todo list. I'm going to need help.

Matt

Been riding a '77 R100/7 all summer, after a 2 year build from a basket case... so I have touched just about every single component and made most of the mistakes.. feel free to PM me if you need pictures, input, or sympathy. We don't always feel like sharing our woes with the world. :

Thanks for the offer, and thanks for checking in Matt.

You guys reminded me that I've been negligent in updating this thread.

In the last two months, I've gotten the cylinders, pipes, and mufflers reinstalled, the oil filter figured out, and changed all fluids. Using a makeshift tank, we got the engine running and went through all the gears. Everything seemed to work o.k., but I wont' really know until I get it on the road. I also just completely rebuilt the front forks.

The tank was completely shot once sand blasted, and I managed to locate a /7 tank (and matching front/rear fender!) in FL and just received it. The paint is beat up, but other than that it looks to be in good shape. Eventually it will be resealed and repainted.

I'm in the process of rebuilding the front caliper and undertank master cylinder, and then reinstalling the front brakes. I sandblasted and repainted the battery bracket and master cylinder, and I primed/repainted the frame under the master cylinder because it was pretty nasty from old brake fluid being on it.

Within a few weeks, this bike might actually be on the road! Not for long though because it really needs new rubber.

After the new tires and resealed tank, next will probably be wheel bearings and maybe new spokes since they're a bit rusty. After that, move onto clutch and transmission inspections, lubrication, and parts replacement, and eventually inspect / replace the steering bearings.

Oh heck, I just did the same thing, same bike, 1977 and in worse shape. Can I get the name of where you sent the tank too, Thanks

matt

I sent my original tank to Moyer Fuel Tank Renu in Pennsylvania:

http://www.gas-tank.com/

It was full of pinholes once they blasted it, so they couldn't do anything to restore it. I wound up finding another tank in FL that I just received. It's o.k. for now but will eventually need to be repainted and resealed.

Here is the bike as of this weekend. Took it for its first ride in about 10 years, albeit through the parking lot. I still need to get the carbs properly tuned and balanced, then new tires and spokes:

Wow, it's been a while since I've been on this site and updated this thread.

As I mentioned earlier, my wife and I had beautiful girl/boy twins in December 2012, and they have been a blast. Hard to believe they are 2.5 years old. We bought a new house and moved in November 2013, and then I took command of a Marine Reserve Battalion in NYC in August 2014. Needless to say, I have not had much time to work on the bike much since starting this thread.

Prior to the kids being born, I did manage to get the front shocks completely disassembled and rebuilt. I also realized the front brake m/c was pitted and beyond repair, so I sent it out to get re-sleeved. Then our kids were born, so the bike sat for almost 2.5 years.

A few weeks ago I finally organized my new garage and got my parts and manual back together again. I have a nicer workspace in my new garage, so that helps.

I repainted the front brake m/c, bought a new brake cable, and got the front brakes reinstalled and bled. They are a little soft (maybe I'm just used to my old 2008 GS), so I think they need to be bled a little better. However, no leaks at the m/c or the caliper!

I put new gas in with Stabil ethanol treatment, charged the battery, and got her started again. I noticed the left cylinder wasn't firing.

I did some more troubleshooting this weekend, after confirming the plug was fine, realized the carb bowl wasn't filling with fuel. Quick adjustment to the float, and the bike is running great! I took it on it's first (rather short) official ride on VA roads! Even with the rough carb adjustment, it ran great, and the clutch and trans were smooth.

The tires are shot, so I really can't ride it much more. Big (expensive) items on the to-do list in order are:

1) New tires. The spokes are rusted, and the rims pitted a good deal. I had looked into having the wheels completely redone about 2.5 years ago (Woody's Wheel works I think?). I need to find the quote, but I think it was almost $1,000 to relace with ss spokes, sand blast and paint rims, and install / balance new tires. Any suggestions?

2) New rear shocks. The originals are pretty shot. Again, this bike sat in the elements for a long time.

3) New pipes and mufflers. I picked the ones on there now up from Beemer Uber Alles for $100 to get the bike running, and they're in rough shape.

4) Reseal new tank, and have all painted parts painted (tank, fenders).

5) New seat.

Anyway, always open to comments, suggestions, ideas. I'm looking forward to at least getting it in ride condition so I can get active with BMW Bikers of Metro Washington and their tech days again, although I don't remember how much airhead expertise they collectively have. If anyone in the DC area wants to swing by one weekend to help me do a once over and maybe reprioritize, I'd appreciate it. Ham radio operators use the term "Elmer" for an expert who provides ham help and guidance to a newbie. I sure could use a local Elmer.

ETA: As she sits today:







A little Saturday evening homework:

Nice job. An airhead can be with you for a long time. Doesn't take much space, can be fixed, resists the high tech redundant answers to questions that never needed to be asked and keeps on going. I've had mine since '87. Last week I finally got around to mounting a saddle I wanted since, oh, about '92. An airhead never stops giving. It's like a friend. Cheers.

Latest progress on the bike. I finally had the spokes replaced, hubs rebuilt, rims polished, and got new rubber, courtesy of Bob's BMW:



As you can tell from the picture, they did a really great job. I installed the wheels yesterday, and finally took it on a real ride for a bit around town.

For some reason, I am getting a small brake fluid leak around the threads of the bleed screw. It is a new screw, and it's nice and tight. Maybe I overtightened it? It doesn't seem to leak when I have the bike stationary and engage the front brake. Strangely, it lets go of a little fluid when I install the dust cap on the bleed screw. Any ideas?

Also, the drive shaft rubber boot has some cracks in it, so it leaks some gear oil, I'm assuming from the drive shaft. Is it normal for there to be gear oil within that boot, or is there another issue or seal problem inside the boot? I've look in the Clymer manual, and can't find another seal, and it seems to be normal to have gear oil from the drive shaft in there. I have a new boot, but getting it installed looks like a pretty major project.

JDC

Installing a new boot on the drive shaft to transmission coupling is not a major job in my book. It's about a medium sort of job.

There is oil in the transmission, driveshaft and final drive. Three place on your bike have gear oil in them. Use 80w90 GL-5 gear oil.

All three places that have oil in them have seals keeping the oil in. The drive shaft is separated from the transmission by the rear transmission seal. It is separated from the final drive by the pinion seal in the final drive. If oil leaks into the drive shaft from either place it's not the end of the World but it should be corrected to cut down on time spent balancing the oil levels.

First order of business is to figure out which seal needs replacing and whether or not more work than just a seal replacement is called for. How many miles on the bike? What other major work has the bike already had?

If you have a transmission with a 100K and the rear seal leaks you would be well advised to rebuild the transmission instead of trying to just replace the rear seal.

Nice work on the wheels from Bob's. They always do good work. I don't blame you for spending this money. Wheel lacing is not for everybody. But the point you are at now with the oil seals is more of a hands on job for most owners. It will take some time. It requires a place to work off the street and hopefully inside. But it's also not for everybody. So You get to decide at this point how much work you are going to personally be responsible for.

This job is not something that needs doing real soon. It can be put off till Winter.

Bob's ain't cheap I know. (quit frankly nobody else is either)

disston,

Thanks for the info. The bike has 47,000 miles on it (speedo works). It had been sitting in a shed for about 10 years or so when I bought it. Thus far I have changed all the fluids, in addition to all the work mentioned above. I have not done anything else to the clutch, trans, driveshaft, or final drive, and I don't know what had been done by the previous owner.

I have room in my garage to work on the bike and keep in various states of assembly. Reading through the manual, I agree, the job just seems like it takes time, room, and patience, as well as some special tools (like the machined down 27mm socket), and all the necessary parts, like the coupling bolts that should not be reused. I bought the bike to learn, give myself something to do, and teach myself some patience, so I'm willing to do the work. I figured it would be a good fall project, so it's good to hear it can wait a bit. In the meantime, I'd like to figure out what's going on with the front brake bleed screw. Would you recommend running a tap in the bleed hole to make sure there is nothing fouled up in there, preventing a seal?

I also need to replace the throttle cables and get the carbs dialed in better.

Regarding the wheels, I debated for a while what to do. However, the bike was basically not safe to ride without new tires and spokes, so I needed to get them done to at least get it on the road. I plan to keep the bike for a while and keep tinkering with it, so I figured it was money well spent.

Thanks again,
JDC

Sounds like your bleed screw isnt seating properly. Get new ones, and don't Harry Hamfist them tight. Just a snugging up will do.