More Mystery Connectors-1985 K100RS

[duddini]

Hi all,

  Well I removed the gas tank on my 1985 K100RS to check the 4-pin connector I had read about that can cause starter trouble. I found a different 4-pin connector not plugged into anything, and I also found two 2-pin connectors just in front of the box of relays not connected to anything. I've attached pictures of these......very curious.  Oh, btw, is there a secret to unplugging the black 4-pin connector ??  I don't see a catch or lock, but it doesn't want to come apart.
  I appreciate all the help I've found here, and don't want to ask stupid questions, but it seems weird to have these open connectors with no mating plug anywhere near them. I've tried figuring it out from the schematic, but wow...no go.

Thanks for any help,
Bob

[Inge K.]

The white plug is for the factory alarm. The 2-pin connectors could be various, easier to give a correct
answer if you tell the colour code on the wiring.

[White Dog]

If you are talking about the 4 pin connector which comes from the gas tank, there are two "wings" on opposite sides which have to be spread open at the same time in order to free the plug.

[duddini]

Thanks for the info guys. One of the 2-pins is a yellow with green stripe and brown, the other is brown and white with a green stripe.

The "wings" seem to be missing on the black connector, probably broken off, so it just must be a bit tight. I'm just trying to be careful and not gorilla anything on this old gal.

Bob

[Inge K.]

The two pin connectors is for additional headlights, one wide beam and one high beam.
The bigger round black connector (which is difficult to separate) in the relay box is a part of that package.

[duddini]

Thanks very much Inge. I have a Haynes and a Clymer, but these are NOT on the schematic.

I love older bikes (I have a 1984 Honda CB650 Nighthawk too), and learning about everything on them is a big part of the fun for me......getting it running will be much better of course  :riding: .

Can I bug you with another question ??  The gas tank has two metal tubes on the bottom right side, I'm guessing they are for venting but the diagrams in my manuals don't show them. Should rubber tubes be connected and directed somewhere lower on the bike, or are they ok just venting below the tank ??

Thanks everyone, this is by far the best BMW forum,
Bob

[rbm]

Can I bug you with another question ??  The gas tank has two metal tubes on the bottom right side, I'm guessing they are for venting but the diagrams in my manuals don't show them. Should rubber tubes be connected and directed somewhere lower on the bike, or are they ok just venting below the tank ??

Yes, your model bike needs vent tubes attached.  Later models of K-bikes had a plastic container clipped to the frame just below those vent pipes to catch water and/or gas overflow.  See the picture below and note the plastic cup in the upper right corner of the frame:





One is not evident from your pictures.  You can always add such a part from a later bike, which is a better idea than attaching tubes directly to the tank.

[duddini]

Thanks Robert, my 1985 does not have a cup. My Clymers mentions "early" and "later" model K100RS's, I'm guessing a 1985 would be an early one. I'll check e-bay and BikeBandit for a cup, maybe I'll get lucky; if not I'll just make something similar.

Cheers,
Bob

[rbm]

Correct.  1983 - 1985 model years are deemed "Early K's".  Model years 1986 - 1993 are deemed "Late K's".  In the transition year, there were a significant number of design changes throughout much of the motorcycle to incorporate lessons learned..

[BrickMW]

Thanks Robert, my 1985 does not have a cup. My Clymers mentions "early" and "later" model K100RS's, I'm guessing a 1985 would be an early one. I'll check e-bay and BikeBandit for a cup, maybe I'll get lucky; if not I'll just make something similar.

Cheers,
Bob

Search for p/n 16 13 2 307 647 - AIR ACCUMULATOR


MAX has them for $2.64

[duddini]

Thanks for the pointer, MAX BMW is an awesome site !!  I have a feeling I might be spending some coin with them  :yes

Cheers,
Bob

[Inge K.]

Don't forget to add a hose to the "cup".

Thanks very much Inge. I have a Haynes and a Clymer, but these are NOT on the schematic.

The round black connector is shown and is titled "Connection for special equipment".

The wiring diagrams is as the standard bike leaves the factory and all the optional
extras that you could add isn't shown.