Ruben...what a sexy...camera.
nzeeman, I repaired a kiev with broken shutter ribbon on one side. It is NOT easy, but it is doable. It needs a lot of patience, it needs new shutter ribbon material, and it needs appropiate tools. Tensioning the shutter after ribbon is replaced can be done with a small screwdriver on the right hand side but don't get stressed if the small tensioning screw escapes a few times before you manage to do this. I 'lost it' (i e lost the tension) at least 50 times myself. When you open it up, you will see what I'm talking about.
The Kievs and Contaxes are module-based cameras. RF module, shutter module, meter module, everything is organized in big functional modules that can be separated relatively easily.
Cleaning out the helicoid for smooth focus is somewhat easier, than shutter ribbon replacement. If that is the problem. You will have to remove the face of the camera, the chrome plating around the lens; one screw is hidden under the leatherette where there's a 'bump', close to the lens opening, above the shutter delay lever. If you have a kiev with meter, this removal might get somewhat complicated. Then you have to remove the screws that hold the ring where the distances are engraved. To get the helicoid out, you probably will need to losen the screws of the rangefinder mechanism/unit (where the little focus wheel is located). Mark the infinite position before you do this, on the two wheels that are coupled (one on the rf module, the other one on the camera body).
In general, try to follow the instructions on the website shown above.
Clean the helicoid, both parts, with a tissue or such, and don't lube (or maybe lube it only by putting some thin oil on your thumb and massaging it on part of the helicopid, rotation will take care of distributing this. But use just a tiny bit!!)
Before putting back together, clean the vf-rf windows from inside. Be careful, don't rub too hard.
The focus wheel itself might also have collected lots of finger grease and hair and dust and such, inside, so it can't properly rotate. You can clean that too, but be careful with the small rotating lens.
It might be that something is deformed inside the helicoid, e.g. somebody forced a lens to couple onm it in a wrong position, and that's why you get a sometimes-easy-sometimes-hard focusing. In that case, try to find a replacement.
Good luck.
