Installing a K1200RS Oil/Water Pump on a K100RS

[Bakunawa]

Hello Gentlemen,

I am in the process of restoring/modding a K100. the original oil/water pump on my K100 is corroded beyond salvation. And part of my build requires me to install an oil cooler. I thought it was a opportune time to upgrade and install a pump unit from a low mileage K1200RS.

The new pump unit lines up nicely on the K100 and would bolt right in. but I have encountered a snag. Pictured below (1st pic attached) is the K1200 Pump unit I have. Encircled is the small gear that is driven from the engine. It would seem that the driven gear is separate from the shaft, as compared to the original one from the K100 that has a shaft built in into the driven gear (2nd pic attached).

It also seems that the original K100 input gear with the built it shaft cannot be swapped in the K1200 pump due to the additional length brought about by the intermediate flange for the oil cooler pick up.

Now, I tried to look into the microfiche for the K1200 to look for a suitable shaft, but I am having difficulty locating that part in the blow up diagram (3rd pic attached).

Does anybody know where I can find that missing shaft in the diagram or know the part number?

Thanks!

[Laitch]

The new pump unit lines up nicely on the K100 and would bolt right in. but I have encountered a snag. Pictured below (1st pic attached) is the K1200 Pump unit I have. Encircled is the small gear that is driven from the engine. It would seem that the driven gear is separate from the shaft, as compared to the original one from the K100 that has a shaft built in into the driven gear (2nd pic attached).

I think the oil pump drive gear in your photo is meant to be used with an engine output shaft that extends through an intermediate pump flange, and is machined with an oblong section in the shaft to engage into that solitary gear pictured in your diagram. The classic K models have pump gears that have shafts machined with two cogs that engage into openings machined on the engine output shaft.

Attached is a photo of K1200GT output shaft indicating the machined area that couples with the pump gear. The K75/100/1100 version of the pump gear can be substituted for that gear with the oblong hole, as long as it has the correct number of teeth and you don't use an intermediate flange for oil cooling; otherwise, custom part engineering will be needed.

I've successfully avoided K1200 motos. Maybe somebody who has actually worked with them will chime in. :giggles

[volador]

Interested to see how this works out. Please post results

09    11 41 1 464 905    GEAR WHEEL   0.12    1     $47.90

https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=51719&rnd=07242017

[Bakunawa]

I think the oil pump drive gear in your photo is meant to be used with an engine output shaft that extends through an intermediate pump flange, and is machined with an oblong section in the shaft to engage into that solitary gear pictured in your diagram. The classic K models have pump gears that have shafts machined with two cogs that engage into openings machined on the engine output shaft.

Attached is a photo of K1200GT output shaft indicating the machined area that couples with the pump gear. The K75/100/1100 version of the pump gear can be substituted for that gear with the oblong hole, as long as it has the correct number of teeth and you don't use an intermediate flange for oil cooling; otherwise, custom part engineering will be needed.

I've successfully avoided K1200 motos. Maybe somebody who has actually worked with them will chime in. :giggles

Ah, That explains a lot! Looking at pictures of the said part, It seems that the output shaft of the early K100 is identical to one on the K1200 except for the longer front end to accommodate the intermediate flange for the oil cooler.

hmmmmm, I think I'll have a nice chat over to my bike wrecker friends abroad as see If I can get one for cheap.

Gimme a few months, and I'll chime back.

[Laitch]

Ah, That explains a lot! Looking at pictures of the said part, It seems that the output shaft of the early K100 is identical to one on the K1200 except for the longer front end to accommodate the intermediate flange for the oil cooler.

I see another major dissimilarity. Regardless, all will be revealed in the fullness of time. Good luck!