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New member of BMW MOA resurrecting 85 K100RS

bruced737

New member
New guy from Wisconsin
Hi to all on this forum. I just joined the BMW MOA after I purchased a 85 BMW K100RS and RT. I got the RS completely torn apart with 160,000 miles and while contemplating putting it back together I had the opportunity to purchase an insurance totaled 85 K100RT with 14,000 miles on it. Totaling this bike happened because it was involved in a low side and broke the fairing and one side cover. The rest of the bike was fine. So I decided since the RT has a salvage title and the RS has a clean title I would tear the RT apart and make sure everything was mechanically safe and correct and get the drive spines lubed. I put the clean titled RS frame on the low mileage RT engine. So far I have replaced fork seals and installed progressive springs, steering head bearings, all the radiator hoses, clutch and throttle cable, rear main seal, clutch basket o-ring, clutch actuator cup. I have also wire brushed and painted the rear diff, swing arm and trany. I have the clutch re-sealed and installed and have installed the trany and mounted the RS frame. Since it is so cold in WI right now I am working on cleaning up the contacts inside the gauge cluster. Here are a few pictures of what I have done on the bike.
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Since I have been working on the bike for the last month I will just put the high lights in the thread and pick up where I am currently.

Thanks to all and I look forward to meeting some of you this summer at the ralley.
 
So I tore the bike down and I found that the rear diff was in good condition. The clutch actuator cup was ruptured and had been spilling oil out of the trany and it made a mess. I was planning on lubing the splines anyway so I am going to replace and check everything as I go. The trany, swing arm and rear diff were quite stained and corroded to I spent a few hours brushing everything.
Before
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After
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once I got the trany off I found some oil in the bottom of the clutch housing so I pulled it and replaced the rear main seal and o-ring. Was a pretty big pain but it's done now and I think I got everything back as it should be. I was very careful to mark everything as it came apart
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With the help of my girlfriend we were able to get the trany back on with out braking anything. I spent the summer working on a snowmobile and believe it or not but the head studs worked perfectly as alignment tools. I replaced the clutch cable and while I was waiting for parts from MAX I replaced the head bearings and races. So I was able to get it installed and I have the left side handle bar controls mounted and complete. I just got the throttle cable so next week I will get that installed.
 
Thanks, glad to be here. I have had time while waiting for my new parts so I started cleaning up the engine and finding all the little things that have not been addressed for the last 29 years. The engine had a lot of corrosion on it so I have been wire brushing it. As I remove covers to check the valves and replace seals on the valve cover and crank cover they will be getting painted to match the rear end. The corrosion came off like powder and I really don't want to spend time polishing it regularly so painting is definitely the way to go.
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When I got the swing arm off I found that the clutch lever cup had ruptured and the bike had been leaking oil out of the trany. It was a huge mess and took me a few hours to get it all cleaned up. I really like the fact you can remove the trany and get access to everything.
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once I got the trany out of the frame I drained the oil and a bunch came out so I know it was not run dry. I will be putting fresh fluids in everything on the bike.
 
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I will be using the RS fairings I have from another 85 K100 I have so I am not sure what I will be doing with the salvage titled frame and spare engine I have. Probably build that bike once this one is done and leave it naked. The body work for these bikes is quite expensive and I am sure it will also need a bunch of parts. At least I have 2 bikes worth of parts to pick from so I will be putting the best parts on the one I am building. I really like the Alaska blue, it is almost the same color as the Suzuki GS1000E I tour on. I will be painting the bike in the future, I just want it to be safe and rideable for now. 20131211_090124.jpg
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I have noticed looking through all the parts that the handle bar controls all look sun bleached and the lettering is worn off. I will have to look into getting that refreshed.
 
I have continued to cleaning the engine. I ran the VIN in a model finder program I got from a BMW site and it says that my bike was made in 84 so I think I may have the euro cams it seems everyone wants. My bike does have the vent at the front of the engine though but it is capped off so I am not sure about this. To me it really does not matter but would be nice to know.
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After a few hours of cleaning I am pretty happy with the results. More to be done but I am making pregress
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Capping the front vent was standard. Leaving the hose connected to the gas tank breather enhanced the chance that gas could be drawn into the crankcase, not a good thing.
When you replace the valve cover gasket, be sure to replace the rubber grommets on the cover bolts. Those grommets apply the tension to seal the cover. The bolts themselves are shoulder bolts, DO NOT over torque them.
 
I have been careful to torque everything to the proper spec. I got the trany re-installed and with some help from my girlfriend it went on with out to much trouble. I did find that I could use the head studs from my snowmobile as guides. All we really had to do was turn the clutch housing a little to align the splines and it slid right in. At least I know I have lubed splines and they are lubed with the correct grease. I got the frame put on and some covers. It's starting to look like a bike again. 20140123_111535.jpg
I have been working on the forks lately, I got them wire brushed and repainted. I wanted them to match the rear end and I thinki they came out looking very nice. I replaced the fork seals and put 10W red line oil in them. These forks must have been done not to long ago since the oil was quite clean and there was very little gunk in them. But I had the stuff already so I just rebuilt them. I installed progressive springs and I made them the same length as the stock springs. I am sure I will have to tweak the length for the correct sag. 20140128_232854.jpg
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My new throttle cable arrived at my house, I have been waiting for it for awhile and got it installed. I also got my right side controls put back together and I found that the grease on the throttle sleeve had become sticky. So I pulled that off and got it cleaned and regreased. Works like a charm now.
 
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I am still not happy with the washed out color of the controls but I will have to live with that for now and figure out how I will reproduce the lettering. The lettering is all but worn away. Next project before the airbox goes on will be to get the pressure regulator and fuel lines insulated
 
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More time to work on the bike this week. I think my progress has been slow to this point but I hope to pick that up next week. I am on vacation and after a weekend of snowmobiling in the Upper Peninsula of Michigan (what I like to call the state of Superior) I should have time to get this thing running. To bad it's still -15 degrees outside. I did get the swing arm installed and rear diff though. The tire is also mounted and secured, I decided to go with dyna beads to balance them.
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Now don't po po me but I went with Kenda challenger tires this time. I have them on a few of my other heavier bikes and I have found them to wear well and have great grip even when wet. If they wear out fast I will put something more expensive on the bike. I have a set on my Suzuki GS1000 that I use for touring and I have loaded that bike down for some long trips and so far the tires have lasted for 6500 miles in the last 2 years. I think they will be good for 1 more season.
Moving on, I also got the side stand and center stand re-mounted after a good cleaning. I found the paint to be in great shape and all I had to do was give it a good bath. I can appreciate the engineering in this bike. I think having some redundancy with the springs was a good idea. I would hate to get 500 miles from home and have the only spring holding the center stand up fall off.
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I have continued brushing the engine cases and I am almost done with that clean up. A few more hours and it should be good enough for the time being. I plan to put a nice coat of autosol on it until I can get them painted. I had a little time and got the inner fender mounted and working on getting the rear fairing. I did find out that I need to get the pegs mounted again before I can finish the rear fairing. I will have pictures of that to come.
 
Thanks a lot, I really appreciate that. I am really looking forward to getting this bike on the road and experiencing riding a BMW. The last time I was on one I was 5 years old and my did sat me in front of him. He had a 1969 or 70 R60-4 I think. I loved that bike, so smooth and quiet. I can still remember the sound and smell of it and that was 38 years ago.
 
I am finally on vacation and since the girlfriend has a cold we have had to scrap out plans to go snowmobiling in the upper peninsula of Michigan. So to save my sanity I have put a bunch of time into the K. I got the exhaust mounted back up and the headers torqued back up. This exhaust is very heavy and hard to manuver into place but I got it done, and the bike didn't even fall on top of me this time. I have had that happen a few times with other bikes. I really like the fact it is stainless and will never rust. When I ran the bike there was no rattles from the heat shield so I think I am good there. 20140215_113654 (1).jpg I am pleased the way it turned out. I did put new studs and locking nuts to hold the header flanges. Hopefully these will not rust of seize in the future.
I got the radiator mounted and found that the fan was messed up so I replaced it with my spare. I used all new hose clamps but I have not filled the system yet. I hope there are no leaks. I am considering putting in a temp gauge so I can keep an eye on the engine temp and I already have a micro volt meter I will install as well.20140215_113609.jpg
Working where I can I got the radiator overflow back in place and the batter and hold down installed. Some one had put a power socket in the bike before so I got rid of the wiring for that. 20140215_113620.jpg
I also trial fitted the rear fairing and got the wires run for the taillight.
 
I did have a nice surprise when I was looking through my boxes of spare parts. I found that I have a progressive rear shock. So now I have progressive springs in the front forks and the rear of the bike. This bike should be a real mile eater this summer. 20140215_113644.jpg
 
Just a suggestion, go to your local hardware store and buy a couple feet of 3/8" ID x 1/2" OD clear Tygon tubing and a couple narrow 1/2" hose clamps. Cut the clamps off the tubing on the sight tube on the radiator overflow tank and replace the tubing with new. Use small regular gear drive hose clamps. Keep the extra tubing so that you can replace it every couple years as it yellows. Total cost only a couple bucks, but really makes a difference.




:dance:dance:dance
 
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I was planning on changing out the tube on the anti-freeze reservoir, thanks for the tubing size. I have had a lot of time in the last few days to work on the bike. I finished the rear fairing and got the luggage mounts on the bike. I will be adding led's to the taillight to make it more visible, you can barely see the brake light. The mounts are hard to see but I think the clean up looks great, I got the foot peg mount cleaned up and some what shined up. 20140217_212942.jpg
I got tired of kneeling so I though I would work on the upper fairing. I got the fairing mounted and tried to follow the cable routing diagram, of course once I for the upper fairing on I realized I had some wires in the wrong place. That took a while to get rectified and the fairing mount was a little tweaked so there went another hour straightening it out. Now it shoud be easy to take the fairing on and off as I need to. I also got the horns mounted and wired back up. I did wind up using the RS wire loom for the turn signals and horns. I did come up with a solution to the problem of the mirrors wanting to fall off when bumped. I am planning on using a cable and a spring to put tension on the housing. It works for my snowmobiles so it should work on the bike. I have rolled my sled and those mirrors get folded flat and spring right back in place. 20140218_115357.jpg20140217_212948.jpg
I found that the weather stripping on the radiator screen was messed up so I cannibalized the one from the busted up RT fairing and got it installed. looks nice minus all the rock dings. When I get the bike painted I think I will protect this area with that 3M plastic stuff for car hoods.
 
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I worked on the forks as well. I got the front brake calipers cleaned up and new pads installed so I should have no problem stopping this thing. I think in the future I will be replacing all the rubber lines with stainless. I really like the way the fork lowers cleaned up and I think the front end looks like new. I will be leaving the mud flap off the bike. I have a fork brace on the bike but its still loose, I will tighten it up when I am sure it wont inhibit the movement of the forks. 20140217_212903.jpg20140217_212913.jpg

I do have a parabollic windshield mount I wont be using so if there is anyone out there who wants to trade me for something I need send me a message.
 
Thanks for this thread, Bruce, I really enjoy reading about and seeing the combination and resurrection.

You should replace all the rubber brake lines now. Rubber degrades with age, and failing rubber lines create all kinds of havoc. Ten years is a reasonable life; these lines have been out in the world for almost thirty. I wouldn't ride around the block with them.
 
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