Author Topic: K100_BBQ_Special  (Read 1215 times)

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
K100_BBQ_Special
« on: August 29, 2018, 05:29:31 PM »
Hello all, Duncan here.

I recently picked up a bbq for a few hundred dollars. It was previously a 1985 K100 commuter bike on the central coast of California. Allegedly ran well until then. SO - I'm going to get it back on the road then go from there. Looks like there was an electrical mishap with the radiator fan, as that was the centrally most melted thing. Will be replacing just about everything between the engine and the tank - including the harness.

The bike is quite crusty but it's all there to start with.

More as parts come in.

- Dunc





  • los angeles
  • 1985 BBQ Special

Offline Skunky

  • ^ Proficient Motobricker
  • Posts: 349
Re: K100_BBQ_Special
« Reply #1 on: August 31, 2018, 05:58:39 PM »
Good luck with your project. As long as the frame has not been weakened by the heat you should be able to rewire OK. Might be worth going down the M-unit path as the loom is damaged.
  • Derby GB
  • BMW K100lt
Rebuild it and they will come..
90 K100lt
Triumph Thruxton 900
Honda CB400F

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #2 on: September 04, 2018, 06:29:30 PM »
Good luck with your project. As long as the frame has not been weakened by the heat you should be able to rewire OK. Might be worth going down the M-unit path as the loom is damaged.

Thanks Skunky.

I sourced a used but good harness on Ebay for $10 so now I have a good starting point. New parts are starting to show up and the bike is stripping down just fine - frame looks fine. No wiring up that far was effected. Waiting on a fuel injector harness to come as well. Picked up some knock off injectors that should be fine to get the bike running with. Here's a down there of of neglected skuzzy parts vs low mileage ebay parts. Replacing the stock fan with the popular spal fan as well.





  • los angeles
  • 1985 BBQ Special

Offline The Mighty Gryphon

  • ^ Quintessential Motobricker
  • Posts: 4291
Re: K100_BBQ_Special
« Reply #3 on: September 04, 2018, 06:54:09 PM »
Looking good!  I just finished rebuilding a bike that was totaled in an accident.  When you're done it will be better than before the fire.  You will get a lot of satisfaction from bringing it back.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #4 on: September 04, 2018, 07:02:32 PM »
Looking good!  I just finished rebuilding a bike that was totaled in an accident.  When you're done it will be better than before the fire.  You will get a lot of satisfaction from bringing it back.

Totally agreed! A few years back I built out a 1987 BMW 325, this bike with the maf based Bosch FI system is identical to what bmw was using on their cars at the time. So not TOO foreign for me just yet. And with the help of some service manual PDF's I printed from the web should be helpful.

Updates as they come.

- Dunc

  • los angeles
  • 1985 BBQ Special

Offline natalena

  • ^ Proficient Motobricker
  • Posts: 273
Re: K100_BBQ_Special
« Reply #5 on: September 06, 2018, 12:47:27 PM »
What a great find and project. The TB cleaned up really nice too. Gonna pull the drives and brakes while you're at it? the front MC and lines might have gotten slow cooked. Good luck!
  • East of Joshua Tree
  • 1987 K75s #0919
On Holy Quest seeking Techron equivalent for splines.

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #6 on: September 06, 2018, 04:00:26 PM »
What a great find and project. The TB cleaned up really nice too. Gonna pull the drives and brakes while you're at it? the front MC and lines might have gotten slow cooked. Good luck!

Yes - once I jury rig the new harness, intake, and fuel system on and get the bike "running". I'll pull the drives to assess and hopefully just lube. Brake lines will be replaced with stainless. Ideally will be going with a more modern master cylinder, not too big, but enough to compliment the factory pots and ebc pads.

Anyone have thoughts on aftermarket springs on the front end?
Either rated for weight from Racetech or Progressives...

I think USD forks are cool and all but I like to compliment and play within whats there already.

- dunc



  • los angeles
  • 1985 BBQ Special

Offline Skunky

  • ^ Proficient Motobricker
  • Posts: 349
Re: K100_BBQ_Special
« Reply #7 on: September 15, 2018, 07:21:49 PM »
Yes - once I jury rig the new harness, intake, and fuel system on and get the bike "running". I'll pull the drives to assess and hopefully just lube. Brake lines will be replaced with stainless. Ideally will be going with a more modern master cylinder, not too big, but enough to compliment the factory pots and ebc pads.

Anyone have thoughts on aftermarket springs on the front end?
Either rated for weight from Racetech or Progressives...

I think USD forks are cool and all but I like to compliment and play within whats there already.

- dunc

There are a lot of Progressive spring kits on fleabay. Personally I think the standard fork seems to do the job admirably. Just an oil and seal change and it's a comfortable ride (and we all like one of those :johnny).
  • Derby GB
  • BMW K100lt
Rebuild it and they will come..
90 K100lt
Triumph Thruxton 900
Honda CB400F

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #8 on: February 01, 2019, 03:17:56 AM »
Make a little progress here. Hopefully done soon.
  • los angeles
  • 1985 BBQ Special

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #9 on: March 22, 2019, 07:40:09 PM »
Hello All. The bike has progressed a good amount in the past few months. More on that later.

I'm tracking down some no start issues. So far the bike has fuel, injectors fire, it cranks, has oil pressure, power is going to the coils, but there is no signal to the coils from the ICU. I've checked the continuity of the wires and they're good.

Does anyone have a hand on how to diagnose this further or best to swap ICU?

  • los angeles
  • 1985 BBQ Special

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6206
Re: K100_BBQ_Special
« Reply #10 on: March 22, 2019, 07:57:29 PM »
Does anyone have a hand on how to diagnose this further or best to swap ICU?
Have you checked the Hall sensors' function?
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #11 on: March 22, 2019, 07:59:29 PM »
Have you checked the Hall sensors' function?

Will rig that up and test now.
  • los angeles
  • 1985 BBQ Special

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #12 on: March 22, 2019, 08:51:27 PM »
Have you checked the Hall sensors' function?


I rigged it up as per in this right up - http://bmwmotorcycletech.info/K100%20troubleshooting%20Starting.pdf

And it doesn't break the LED illumination. So it appears that's bad at the least. HA. Will source that then see if the ICU is bad.
  • los angeles
  • 1985 BBQ Special

Offline Jared

  • Curious
  • Posts: 2
Re: K100_BBQ_Special
« Reply #13 on: March 27, 2019, 06:26:53 AM »
I brought those knock off injectors on eBay from a guy in California and the flow rate was way too high, I'm surprised it started it was running so rich. i couldn't use them at all, i had to clean the old ones up and put them back in.
  • QLD, Australia
  • 1985 RS K100, 1987 RS K100

Offline duncwerks

  • Motobrick Curious
  • Posts: 12
Re: K100_BBQ_Special
« Reply #14 on: March 27, 2019, 12:21:32 PM »
I brought those knock off injectors on eBay from a guy in California and the flow rate was way too high, I'm surprised it started it was running so rich. i couldn't use them at all, i had to clean the old ones up and put them back in.


Well I suppose when I get it running we will see about that.
  • los angeles
  • 1985 BBQ Special

Tags: