I had a mate with MS who needed to go to Russia for stem cell replacement and needed money.
I saw this old K100 and thought it would be a qiuck re-assemble and then flick it.
Things got busy and the K sat while we went to Russia and back. 
So 12 months later, after helping another mate with his bike, he offered to come look at the K. He later told me that he had thought I'd gone mad and that the ugly thing was a money pit..LOL
[url=https://servimg.com/view/19484052/5][/url]
It had been down a bank, upside-down and sat for 3 years before I bought it.
We replaced the oil & filter, new battery, topped up the coolant and thought we might try an start her. Fired up after a few tries and ran.

Hey welcome to the land of Ks and she does look a good one.

Check out the fuel filter though, old bad petrol and crud in the gas tank can KO the fuel pump, usually better to do this before firing up. But good to see she is running.

Check the home page on what to do if you have just bought a K. One thing for certain, the fuel lines from the tank will be old and hard and liable to crack and spray fuel as they are all pressurised. Replace them and use BMW line, its cheap. Make them a little longer and you wont have to disconnect them to access the coolant cap or the electrical box under the tank. Spare room in that electrical box for a few bulbs and fuses etc, just undo the bolt and lift the rear of the tank to access it.

Thanks Olaf.
Thanks for the advice and the welcome. 
I should mention that the bike is well on its way to completion with much information gleaned from this forum.
 its only at this point (Cold weather) I thought Id post the build blog for the benefit of others.

Thanks Bob.

That's what the forum is for.

I was forgetting your weather is upside down too. Sun out here.

So, are you still going to flick it or have you contracted Kpox?

Well, when we started it, there was this white 'smoke' coming from the exhaust.
My head went..'OIL.....rings..'.I thought seriously about ditching the thing, but if others can fix them, why not I?  So we left it for a week while I talked to a few others. One suggested the muffler could be full of water ~ Steam.
I removed the muffler stood it up for a day or so then replaced it,I then started it.. SMOKE!  Another said that the mufflers were filled with Aluminium wool ~ Aluminium Oxide fumes so, again removed it, and started it = NO SMOKE .
So I cut the muffler and removed the big baffle. Problem solved.
The engine had a knock at idle so off came the crank cover to investigate.
#1 big end bearing shells needed replacing.2 weeks later they arrived & were installed as per the Haynes manual that came with the assorted extra parts.
I was making progress

Thoughts of just where this build was going at some stage came to a cafe style.
Im not ready for the touring, full fairing style yet it still needed something to cover that radiator. Inspiration..Google images pointed to the basic cowling but OMG were those hard to find.UK,USA,AUS,FR & GERMANY..NOTHING OEM. But the obvious change was the handle bar/ instrument combo. It just seemed too tall..
After a week or so, searching the net, the bars arrived.
While installing I lowered the front 25mm which really changed the profile.
By chance, I stumbled on a full set of used Radiator cowlings ($1K )
At least they were local and  the right color. All up, so far not including consumables, $2400.

I received the belly pan ex Germany and fitted it considering the oil and filter had been done It really changed the shape giving the bike depth.
Now the seat and tail.
I realised the power this bike had and thought hard about the seat. A simple flat bench wouldnt look right and Id probly slide back a lot. And the 'gutted frame' look didnt appeal. Anyhow I had ordered new battery covers
Musing with my mate one afternoon, we decided to try keep the tail 
(less the lighting!)
 
It started looking a lot better but the lines of the side covers needed to be kept.