Oil/Water Pump

[swells]

I have an '87 K75S with ~46,800kms showing and I bought it late last fall with 43,500kms. Since then, I checked and/or fixed all the “weak” areas. I now have a new drive shaft to show for it. I have one concern left, the oil/water pump. I have read a lot of informative info on the subject. So far, I don't believe that I have any problems with my oil/water pump I have checked the weep hole and it looks relatively clean. There is a thin layer of oil and dirt that starts at the cam chain cover and continues down around the pump and along the sump pan. If it didn’t have the lower fairing covering the mess, I would have been frantically scrubbing and replacing seals. I have never seen signs of an oil drip, except around the valve cover which now has new gaskets to seal it back up. But now I am concerned because it's 21 years old. Of course I am assuming that the previous owner hasn't rebuilt it either. My plan was to leave it alone until next fall figuring that I would not travel more than four or five hundred kms from home. If it failed completely at that distance, I could find a way to truck or trailer it home. A month or two ago, I started thinking about taking a 4 or 5 day trip this summer which started me thinking about the pump again. So I ordered new seals and o-ring gaskets. I could only get the water seal with the blue gunk/silicon sealant. From what I was reading, it is a direct substitute for the older rubber and plastic one.

My question is regarding the older pump model. The one that the rotor threads onto the shaft and is held with a nut rather than the one with a smooth shaft and the rotor is held by a bolt. I suspect that my ’87 being built in March of ’86 has the older style rotor and attachment style. From what I have read, it is suggested that these also be replaced with the newer style. From what I see, the price for the new shaft, rotor, nut and spacer is ~122 us plus shipping etc. Are these pieces really necessary or will the new seals work with the old shaft style?

Bert, I was looking through your K100RT winter project site again today, looking for something completely different (what an informative site), and I noticed that your pump has the older style shaft? Did you reuse that shaft and rotor or did you buy the newer type. Were you able to get the older seals or did you use the one with the blue sealant?