The Stellar Turbo K100

[stellarkyle]

Hello all!

I'm happy to say I finally got my bike! For those of you who didn't see my other post, I purchased a 1985 K100RS from a guy on Craigslist in Hawaii. I officially bought the bike at the beginning of May but it took until the end of June for it to make to me here in Georgia. I was eager and nervous to get her since I had bought it sight unseen. I had a local mechanic who is familiar with flying bricks look it over for me so I wasn't going into the deal completely blind, but it was nerve wracking nonetheless. She's in kinda rough cosmetic condition, but runs really well. There's some rust in places and the paint everywhere has seen better days. The turbo appears to be functioning as it should because it HAULS. The turbo kicks in right at 5k RPM in any gear and really flies. I'm planning to get it dyno'ed as soon as I'm done with regular maintenance to hopefully shed some light on the actual power of these turboed bikes.

Here's my new Hawaiian girlfriend!


The bike has a Luftmeister (RB Racing) turbo kit on it as well as a couple other Luftmeister add-ons. For starters, Luftmeister widened the rear wheel. It looks like they cut it on either side of the snowflake, added spacers, then welded it back together. I don't currently have a close up picture of it but can provide one if anyone is interested. The bike also has a WP rear shock.

Here's my immediate to do list:

• Change Engine Oil and Oil Filter
• Change Brake Fluid
• Change Coolant
• Change Final Drive Oil
• Change Transmission Fluid
• Change Fork Fluid
• Change Fuel Filter
• Check Air Filter
• Check Spark Plugs
• Lube Splines
• Replace Head Bearings/Races
• Rebuild Leaking Front Brake Caliper
• Get the bike running again...

*Updated 1/23/17

My plan is to do all this maintenance over the next couple weeks and ride the bike through the end of the season then tear into it this winter. We'll see how the timing goes though since I'm still finishing my undergrad and will be in school this winter. I'm wanting to make some big changes to the bike and have some renderings if anyone is interested. My plan involves new fairings and keeping the 80's vibe.

I'm thrilled to officially be part of the motobrick community and am looking forward to sharing this project with all of you! I'll share the progress I've made so far as soon as I figure out how to insert pictures... I've tried multiple photo sizes in both Flickr and Photobucket but they still don't show up in the post preview...

[Laitch]

Click the Attachments and other options link below the Post reply box and use that function to post the photos from your computer. Attach the first one then click more attachments and continue attaching as many as you have. Size them to around 10 inches and 72dpi. They aren't going to show up in Preview; they'll show up when you click Post.

[stellarkyle]

Click the icon at the point of the red arrow to download from Photobucket or some other host. You paste the photo's URL in the box that appears.

Thanks for the help. Seems to be working now even though I did the same thing as before.

[stellarkyle]

One of the first things I noticed when riding the bike was that it is a bear at low speeds. I've ridden heavy bikes before but this was different. I tested the head bearings moving the handlebars back in forth with the bike lifted up so the front wheel was off the ground. The steering felt pitted so I went about removing the front end.






The "grease" was like plastic.




The upper and lower bolts on the right side of triple tree both stripped when we took them off even though we used liquid wrench and heat... My replacement bolts will go on with anti-seize.


I've order All Balls 22-1024 bearings to replace the current ones. They won't arrive until next week so I decided to repaint the forks in the meantime.




Peels right off.


The blue paint required paint stripper.


All cleaned up.



Primed with etching primer.




Painted with Rustoleum Satin Black. I don't know how long the paint on the forks will last but at least it's better than before. I really like the look of them bare metal so I may take it back to that at some point.


Last but not least, the odometer wasn't working. Opening the instrument cluster confirmed my suspicions. The gears are completely disintegrated.




At this point, I think I'm going to run without an odometer for a little while. I was wanting to replace the cluster with a Motogadget or Acewell unit anyway so I'm just going to save the $85 on replacement gears and put it towards a new unit.


PO said the gasket ring on the fuel tank started leaking as he was riding it to the port to drop it off. He was nice enough to send me a check for the replacement which I just put on (Part #16 11 1 453 690)

[stellarkyle]

Everything is back together and I took it out for a ride Sunday afternoon after re-bleeding the brakes. Even though we bled the brake very thoroughly, they were a little soft. I thought there might be some bubbles in the system that may shake out with some riding. The brakes only got softer so I cut the ride short. Back at the house, I found brake fluid slowly dripping down the rotor from the front right caliper. I took the caliper off and found one of the O Rings was intact but the other was a little mangled and drenched in fluid. I'm going to pick up a caliper rebuild kit (Part # 34112310493) from my local BMW Motorrad store on the way home from work so hopefully that'll solve my problem!

[furnimoto]

My plan is to do all this maintenance over the next couple weeks and ride the bike through the end of the season then tear into it this winter. We'll see how the timing goes though since I'm still finishing my undergrad and will be in school this winter. I'm wanting to make some big changes to the bike and have some renderings if anyone is interested. My plan involves new fairings and keeping the 80's vibe.

Congrats on the new bike, post your renderings!

[stellarkyle]

I used the kit to rebuild the caliper. Everything looks fine after bleeding the brakes and there's no sign of leakage!

Congrats on the new bike, post your renderings!

Thank you so much! Here's what I have so far:



I'm a big fan of the endurance racers from the 80's so that was my biggest inspiration for this project. The two biggest things I wanted for this build were to have fairings of some kind and for it to look period. I've sourced some fairings that should work well from AirTech that shouldn't require too much modification. I'm currently thinking I'll use a tire fairing off of a S1000RR. In the spirit of an endurance racer, I'll put dual headlights up front. I'm thinking I'll go with 90mm units from HELLA or PIAA. I'd like to blackout the engine then strip and polish all parts of the turbo setup to make it really stand out. I've not totally settled on the paint scheme. I like the white base with the M Motorsport stripes. I'm trying to find a way to make it look like a race bike without sticking a number and decals on it.


I'd love to get feedback on what I have so far! I'm sure there's plenty of problems/complications that I haven't even considered yet.


Photo dump of some of my inspiration:

PRAËM X BMW S 1000 RR



Luftmeister's landspeed bike



WhiteHouse CB750 Motorimoda



WhiteHouse RCB1000



 Walt Siegl's MV Agusta F3 Bol d’Or’ Racer

[BRIDGE]

All nice looking references, but personally I'd go with something similar to the Luftmeister landspeed bike (that thing is beautiful!). Have you seen the guys over at BSK speedworks have made and endurance racer? looks like the sort of build you're after, or if you want to really challenge yourself I know someone made a replica of the JJ Cobas K100 endurance bike

[stellarkyle]

All nice looking references, but personally I'd go with something similar to the Luftmeister landspeed bike (that thing is beautiful!). Have you seen the guys over at BSK speedworks have made and endurance racer? looks like the sort of build you're after, or if you want to really challenge yourself I know someone made a replica of the JJ Cobas K100 endurance bike

That would definitely be cool! I'm not sure if I'm up for fabricating all of those fairing from scratch. I haven't seen similar fairings on AirTech.

Yeah, I've see BSK's bike! I didn't realize until now that it's such a similar paint scheme.

That JJ Cobas replica is bookmarked in my inspiration folder! It's a really cool build. I think that with all the turbo components, it would be better to do a 3/4 or 1/2 fairing instead of making a full fairing to fit around all of it. Plus, a 1/2 fairing will show off the turbo better. :)


Sent from my iPhone using Tapatalk

[BRIDGE]

+1 on the showing the turbo, if you've got it flaunt it. Was just checking our airtech as it's always nice to dream but pennies are short so can't get a new seat anytime soon.


I did find these though http://www.airtech-streamlining.com/landspeed/landspeed.html so it would be more fabricating the brackets for a luftmeister look

[stellarkyle]

+1 on the showing the turbo, if you've got it flaunt it. Was just checking our airtech as it's always nice to dream but pennies are short so can't get a new seat anytime soon.


I did find these though http://www.airtech-streamlining.com/landspeed/landspeed.html so it would be more fabricating the brackets for a luftmeister look

The link didn't seem to work for me. It worked for me without the "L" at the end. http://www.airtech-streamlining.com/landspeed/landspeed.htm
Those are definitely close to Luftmeister but I think I still prefer the endurance style more. I plan to start working on the fairings this winter so there's still time for my plan to change.

[BRIDGE]

I'd also say going with an endurance fairing would be much more practical and have much more longevity

[Christopherguzzi]

Might be a good look to go with different headlights, a la an s1000rr.  When they first came out I thought it was pushing the envelope, but it quickly grew on me as you have to give BMW credit for their bold styling.

[stellarkyle]

Might be a good look to go with different headlights, a la an s1000rr.  When they first came out I thought it was pushing the envelope, but it quickly grew on me as you have to give BMW credit for their bold styling.

I'm not sure I totally get what you're saying. It also looks like the link to the picture is broken. Are you saying I could use the lights off of a S100RR on my bike?

[stellarkyle]

I had an eventful evening! I took the bike out for another test ride to make sure the front brakes were still behaving well when the rear brake decided to work... Really well... When I didn't want them to... The bike got a little sluggish and I immediately noticed the psi gauge for the turbo went from 10 psi (where it always is - even at idle) to 0. I thought something went out on my turbo so I spotted a place to pull over a few hundred feet ahead to take a look. Only it got much worse from there to where the rear tire completely locked up the in last couple of feet.





As soon as I stopped, I noticed smoking coming from behind me. The rotor was bright orange. It was much brighter before I took this picture.




Hey, at least now you guys can see the welds where Luftmeister added the spacers for the wider wheel.


My friend who has a truck and ramp is out of town but, thankfully, a Good Samaritan, who also rides, stopped and offered to get his truck and ramp and bring me and my bike to my house. We just dodged an incoming thunderstorm and I haven't had a chance to tear into the bike yet.

All this to ask, "What are the standard parts to replace after a rear tire lock-up?". I'm pretty sure the rotor warped because it catches on the pads all the way around except for around the small area where the pads were clamped down on the rotor as it cooled. The plastic dust cover is completely melted too. I'm mentally bracing for the worst: new rotor, new pads, and new caliper or at least another rebuild kit.

Does anyone know what could have caused this and how it could have been prevented?

[Mike Flores]

I had something similar happen on a classic Mercedes Benz car that I owned, one of the calipers basically locked up like on your bike. Here's what I think happened:


Your brakeline is really old, and has started to fall apart on the inside... the rubber in the line that has broken down might be "flapping" inside the brakeline, creating a one way valve. Basically, everytime you touched the rear brake, the brakepads compressed against the rotor, but when you released the brake lever the pads stayed pressed down instead of backing off. Each subsequent press of the lever cased the caliper to brake harder, building up all that heat, and once you slowed down enough for the wheel's rotation to not overcome the braking force, it locked up.


If I were you, I'd replace the caliper with a freshly rebuilt one, along with brake pads, rotor, and new brakelines. I'd probably also rebuild the master cylinder while you're doing all that.

[Christopherguzzi]

I'm not sure I totally get what you're saying. It also looks like the link to the picture is broken. Are you saying I could use the lights off of a S100RR on my bike?

Sorry about the link that is not working, just meant to say different headlights on each side of the fairing would be cool. Don't need to be BMW headlights specifically, but just different on each side.

[stellarkyle]

Finally had time to take a look at the damage. Here's what I found. All the gaskets where completely fried.






The rotor was visibly warped and it had deep grooves in it. A new EBC MD611 Brake Rotor is on it's way. Also ordered new EBC FA18 brake pads all around.



I'm going to get a new gasket kit and see if I can re-use the caliper. If it doesn't seal, I'll get a use caliper and put the new gasket kit on it. I'm also going to rebuild the other front caliper while I'm at it. Later this week, I'm going to take off all my brake lines and see if a local hydraulic shop can build me stainless steel braided lines.

Where do the two small O Rings in the caliper repair kit go?



Do they go on the bolts or here?

[stellarkyle]

Where do the two small O Rings in the caliper repair kit go?



Do they go on the bolts or here?

Anyone have an idea?

[BrickMW]

Check out THIS thread...

[stellarkyle]

Check out THIS thread...

Thank you! This didn't show up when I searched for it before. I think I searched "caliper rebuild" instead of "brake rebuild".


So according to his pictures, you only use ONE of the O rings?

[BrickMW]

That example is a FRONT caliper... Looks like your REAR caliper has two fluid passages which would require two o-rings.


Sorry I'm not more familiar... I am blessed with a drum brake.


I faintly remember reading a thread about a rebuild involving extra "not used" o-ring/s, but after searching, I think it might have been about a fork rebuild, not brakes. I can't seem to find it now.


Does each half have an opposing "stepped" recess on one of the holes? i.e. a place for two o-rings, one on each bolt, seated in recess on opposite halves? If yes, I would say mystery solved.

[propav8r]

Man, I wish Photobucket hadn't gotten so greedy about embedded images. They erased a huge wealth of knowledge online by that one boneheaded move.

OP, could you consider rehosting your images somewhere else? I use Imgur and have been very satisfied.

[stellarkyle]

Man, I wish Photobucket hadn't gotten so greedy about embedded images. They erased a huge wealth of knowledge online by that one boneheaded move.

OP, could you consider rehosting your images somewhere else? I use Imgur and have been very satisfied.

Thank you for pointing that out, Propav8r! In the next couple days, I'll re-upload all the pictures to imgur.

[stellarkyle]

Finally got around to reuploading all the pictures!


Time for a little progress up date. It's hard enough to find time to work on my bike when taking a full class load and working part time and even harder to post about it!


I had a local hydraulic shop make some steel braided brake lines for me.



Also got the EBC rotor installed.




Instead of paying $150 for a new master cylinder from BMW, I picked up a MC from a 2009 Yamaha FZ6R on eBay for $18. It's reservoir is a little smaller than the stock, but ended up not being a problem at all. It stops better than stock ever did. I had seen the threads where guys would take the generic Chinese MC's and put them on their K bikes. I liked this idea but wanted a replacement that was Brembo and also had the hose attachment on the top instead of the bottom so bleeding the brakes would hopefully be easier.




I did all of this a couple months ago so I don't remember all the specifics. I started off by sawing off the extra length of bolt of the "plunger".




Then I drilled a indention in the bolt so the nub on the brake pedal would sit properly.




If I remember correctly, the mounting bracket for the K100's MC are 45mm but the Yamaha MC had holes 50mm apart. I simply drilled the holes a little closer together.




So far the new brakes have worked out great!


Other maintenance I've completed is replacing engine and gear oil, oil filter, fuel filter, and replaced the coolant with Engine Ice.


When I went to check the air filter, I found a fun surprise! This turbo bike was set up with a pod filter instead of an air box. I really love the look!