Hello and greetings from Sweden. I am a fairly new owner of a 1984 K100 that I'm in the process of rebuilding.

Välkommen! Lots of knowledge on this forum to help you with your rebuild.

Welcome from Ireland too. I also have 1984 K100 RT.

Excellent bike and one that will serve you well in all weathers.

There is great knowledge on the forum, everyone is very friendly and helpful so do not be afraid to ask any questions, someone will have an answer. Always ask questions before spending big money on parts....

There is a section on the home page for what to do if you have just bought a K bike. Have a good look.

A little tip, a lot of electrics under the petrol tank and you keep having to take the tank off to get at them and to get at the coolant top up on the radiator. Replace the fuel hoses as they are under pressure and with being old they will break easily. Use the BMW fuel line, they sell it in a length of about a metre and you cut it to suit, But, put longer ones in so that you can lift up the tank to access the relay box without disconnecting them [put the connectors in a position where you can get a screwdriver at them without removing the fairing lowers too] You will also be able to move it back far enough to access the radiator cap. It just means you then do not have to depressurise the fuel system every time you need in there. The electrical connection to the front left side of the petrol tank is also known to cause intermittent trouble so clean the connections on that and open them up a fit to make sure its a good tight fit.

If you do all the small things the K is a very reliable bike.

If you do get the travel bug do make a trip over to Ireland. You will be very welcome.

Olaf.

Thanks for all the advice Olaf. I have read a lot of interesting bits here and there on the forums and will change the fuel hoses as you recommended. I've just finished the front forks (changing fork seals and oil) and are working my way backwards. I have stripped the bike naked and I'm currently working on changing the speedo (the one on mine was in really bad shape). Working out the electrics on this bike has been a blast so far and the information here has been invaluable. Trying to convert the speed signal to a more aftermarket friendly signal.

This old bike hasn't been taken care of by previous owners so I'm going to change all the fluids and filters. Not sure if I should re-grease the splines on the drive shaft, the bike has been through almost 100 000 km. Any others things that a new K100 owner might miss? =)

If you are doing that much I think you will be advised to regrease the splines and quite possibly the input shaft as well. If it has been sitting this could be important.

The seals and rubbers all suffer and some are not so difficult one. I would do the injector seals, not hard to do, but the intake manifold rubbers also crack with age so keep an eye on them too.

The most problematic one is the crankshaft output seal behind the clutch. If you have the tools its a known problem area after 30 years and you can do the output shaft splines, replace that seal and check out the clutch at the one time. 88KE here did that job last May.

While you are at the fuel hoses there is one between the injectors and the airbox connected to the fuel pressure regulator. Do that one too, its the same type of fuel line. There is also a rubber crank case breather pipe behind the injector rail, on the right, it cracks and messes up the running. These are easier to do if you can get the airbox off....but there is an Allen bolt inside it that can be hard to move and is hard to get at as well so plenty of WD40 or some other means of getting it loose. You just might end up cutting the bottom half of the airbox to get it out......

All the electrical connections need to be cleaned out and sorted, the components themselves are good and reliable but the connections are now old and could be unreliable.

A word of warning...if the battery is low do not try starting it if the starter motor is struggling to turn over. Charge the battery first. If you keep trying it you can destroy the starter relay.....it welds itself together and you might find it stays turning over after you let go....disconnect the battery if that happens.

Have you had the K running?

welcome aboard ...have fun !!

92KK 84WW Olaf wrote:
Have you had the K running?

Yes I have and the engine and gearbox are smooth. Ive only done about 150-200 km on the bike before I started tearing it apart (back in september when i bought it). Thank you so much for all this information, we'll see how much I decide to change this year and what I leave to next winter.

Regards
Tom