Bought this '89 K100 from a friend as an unfinished project, he was going for cafe racer (was originally an LT). I'm not a fan of clip ons so doing something else with it.

As it stood when I got it home.





Didn't run, fuel pump was seized, runs OK with a new one (bit loud with the open pipes). Changed oil and filter. Got a new radiator as both that came with it leaked.

Removed clip ons and changed fork oil, fitted a set of 6" rise bars.



Cut off the rear frame piece the P.O. had made and fitted a fiberglass tale unit. Rear light is from a YZF R125.



Need to get a 7" headlight to fit my nosecone fairing next so I can mount it.

Made some more progress recently, just indicators to get for the front then lights are ready to wire in.

Yep so far so good

I like the Bubble! Looks like the front end is shaping up. 

The hardest thing, in my humble opinion, to get right with these K customs is the seat, due to the angular shape of the tank and the sweep of the rear frame. 

So many of them have been done with flat planks or seats that make them look like they have a broken back. watching with interest.

88

The sore point to me on almost every K bike cafe project is the upswept bottom line of the rear half of the fuel tank.  It does not flow properly into the plank seats these bikes are known for.

I have only seen one bike where this line was addressed(made level) by(I assume) raising the front and lowering the rear mounts.  Yes, the filler is now angled, but the effect on the overall look of the bike is amazing.

Thanks for the encouragement, got the clocks mounted last night and ordered a battery.



As to the angle of the fuel tank, I hadn't thought of that (not much space left in garage to stand back and look!). Will have a look next time I'm in garage but I'm trying to get this finished for spring so might stay the way it is for now.

Not updated this thread for a while, I always forget to take pictures as I go!

Removed all unnecessary wiring and connections, and wired in Suzuki switch gear with an LED indicator relay. Machined an adapter to use the BMW clutch cable with the Suzuki perch.






All electrical work is now done, with lights all fitted.

A WHAT perch!? (heaven help us)

Looking very tidy so far, what sort of adapter is it 8mm to 10mm on the adjuster or nipple?

rawdonball wrote:A WHAT perch!? (heaven help us)

SUZUKI. Also has Suzuki switchgear, master cylinder and headlight. Rear light and throttle tube are Yamaha. Choke pull is Honda. Will see if I can work some Kawasaki in too

K75cster wrote:Looking very tidy so far, what sort of adapter is it 8mm to 10mm on the adjuster or nipple?

Thanks, the adapter is threaded M8 for the Suzuki perch, with the end cup sized for the BMW cable.
The adapter is slotted for the cable to go through the side as the end of the cable is too big to pass through the center.
I milled the lever to accept the 10mm nipple as it was 8mm originally.

Have painted the seat unit (was black gel coat before) and put everything together so far.
I have ordered custom brake lines, waiting for them to be made.
Still need to sort the throttle cable. I got a Hayabusa one but it's too short, so will need to think of something else.

I'd look in the trailbike department, they'd have our 22mm bars and perhaps many more throttles and cables to use.
What brake master are you using, is it about the same size as our 13mm master cylinder bore?

Got one ordered that should work now.

Master cylinder is from a GS500, it's a 1/2" bore so 0.3mm smaller but can't see that making any difference. Stroke measures the same as original.

Yes that should mean the braking power goes up in your favour by 0.3 and the lever travel will increase by 0.3, so you should not really pick the difference, sounds all good.

My lines turned up so I fitted and bled them, lever feels OK, will see how it is on road when bike is finished.

Also got a Yamaha YBR 125 (fuel injected model) throttle cable to fit, just a couple of adjustments to bracket were required.

Have ordered new tyres as the ones on it are cracking. Couldn't find radials in the sizes I wanted so went for BT45s.

Still need to paint the fuel tank, make a fuel cap, exhaust and do some more small jobs, then I'll pull the gearbox ect. for a spline lube. Also need to pull the throttle bodies as the inlet manifolds look to be in a bad way.

Pulled the throttle bodies, inlets manifolds are usable, need to clean this lot up. I have fitted a breather filter to the crankcase so this won't happen again.



Fitted my new tyres, then stripped the back end down.




Pulled the clutch out to check it, good job I did, was able to clean it up OK. Friction plate is in spec.




Clutch push rod boot didn't have much left of it, this has allowed sand/grit into the box, someone had been using it like that for a while as the piston and bore are scored a fair bit. Flushed it out with a solvent cleaner, will change oil again after a couple of uses and see how long it lasts


The side stand had a lot of play in it, letting the bike lean far too much, I machined a new bush and bolt for it. Have removed the center stand, but will keep it in case I decide I want it back on.

Now waiting on bits from Motor Works - clutch boot, driveshaft gaiter, alternator rubbers, final drive breather and all fill/drain washers.

Yes they sure can be treated harshly, thanks for the update.

It's back on it's wheels now, also fitted mirrors and it's 'MOT' number plate and reflector. Made infill panels round rear wheel to keep water/dirt out.



Cleaned the throttles and collector box. The intake manifolds and rubber boots were all hard, soaked them in wintergreen oil and IPA to soften. Note to self - don't use an ice cream tub next time. Also ran the injectors through my ultrasonic cleaner and fitted new o rings.



Fitted a cone filter and coolant expansion tank. Filter will be shielded from hot radiator air at a later date.



Currently painting fuel tank, then need to make an exhaust + a few small jobs.

You sure know how to trash an ice cream container LOL
Looking forward to the paint job

half brick wrote:It's back on it's wheels now, also fitted mirrors and it's 'MOT' number plate and reflector. Made infill panels round rear wheel to keep water/dirt out.



Cleaned the throttles and collector box. The intake manifolds and rubber boots were all hard, soaked them in wintergreen oil and IPA to soften. Note to self - don't use an ice cream tub next time. Also ran the injectors through my ultrasonic cleaner and fitted new o rings.



Fitted a cone filter and coolant expansion tank. Filter will be shielded from hot radiator air at a later date.



Currently painting fuel tank, then need to make an exhaust + a few small jobs.

Where did you purchase your coolant expansion tank? Or did you perhaps make it yourself?

It's a 500ml aluminium drinks bottle from eBay.  The cap thread is 3/4" BSP, I used a hydraulic blanking plug drilled for the hose with a small breather hole beside it.

Got the tank finished, have also machined an adapter from stainless to fit a Monza style fuel cap. Stainless side panels too. Cut down foot peg hangers.






Just waiting for 'choke' cable (although starts OK without it) and still need to make an exhaust (bit loud at the moment with open headers). Then it's MOT time!

This does look like a fun bike

Thanks, can't wait to get out on it

Had an issue with the coolant warning light and fan coming on when cold, sorted now with another relay.

Balanced the throttle bodies and set the idle, runs a lot nicer now.

I've made an exhaust for it, not fitted yet but no way it's MOTable, so fitted this mint condition stock exhaust to get it through.

Just need to sort insurance then I'll book MOT

If you've got a picky MOT inspector then that pipe will fail too. Something somewhere about the exhaust not protruding beyond the rear of the bike.

It looks like that in the picture but the rear tyre is actually the rearmost point (unless you mean beyond the bodywork)

It's booked in for Friday so will find out!

Got a pass yesterday, but had an advisory for the rear wheel touching the bodywork when compressed.



Going to have to cut off the end piece I made to close off the frame and make a curved one to get more height.

The rear light would get ripped off though so I'm going to have to move it higher if I can, but will probably have to use a different one.

I got different front indicators. Need to get different number plate light as well. Fitted 'choke' cable to side panel.




Fitted my DIY exhaust and wrapped it. Need to get lock wire instead of those clips. It's every bit as loud as it looks  

Rides well with a fresh tank of fuel and it's throat cleared but not using it again till I've changed rear end.

Changed the back end last weekend so it doesn't rub. Moved the number plate in and fitted a different plate light. Extended the vertical rear panel sides to hide the battery better.



Made a radiator guard and replaced the rusty screen bolts.



Changed the clips on the exhaust wrap for stainless MIG wire, looks a lot better but it's just a bit too loud, getting a buzzing vibration through the seat which I think is because of the exhaust as well.

At some point I'll make a collector from scratch and use a slip on, but got a big back log of other jobs I haven't done because of bike taking all my time so will have to stay as it is for now.

Other than making make a belly pan for it (one day) I'd say it's pretty much done (if that ever happens with a project!)