K100RS Weeping intake manifolds

[weiner]

I have a 1985 K100RS with approximately 60,000 miles. I am the original owner. I am planning to ride to the MOA Rally next week. Today while doing some minor service work with the fairing lowers off, I observed that the number 1 cylinder intake manifold has been weeping and the number 3 rubber bushing above the throttle body is weeping also. I've introduced propane gas with a unlit torch at all of the throttle bodies areas and the RPMs did not change.

All of these parts are original and I know I need to replace these 38-year-old components. But I don't have the parts or the time to replace the components before the rally. I would like to ride this bike to the rally which is only 200 miles away. I would like feedback from some of the more experienced K bike owners as to their opinion if this would or would not be harmful to the engine etc. The bike seems to run fine. See picture below.
Thanks in advance!



View attachment 92003

 

[52184]

Order the bushings and other bits you’ll anticipate needing, tuck them into a saddlebag, and enjoy the rally! At that age and mileage you’ll also want to think about replacing the $$ breather hose assembly that runs from the crankcase up to the FI bodies, as a “while we’re in here” sort of thing. They have a tendency to crack at the “y” junction and start creating problems.

Enjoy the rally,
DeVern

 

[98lee]

Weiner,


You should have no problems. Your propane test indicates that they are not yet sucking in any air and it is running well. 400 moles round trip should be no problem. Go to the Rally! Relax and have fun. Plan on dealing with it when you get back and have more time.

The Z shaped crankcase vent hose in between the plenum (above the throttle bodies) and your coils is a bit more likely to cause problems if cracked. It is not as expensive as later Kbikes. From the dealer, they are $24.38. From Euromotoelectrics they are $15.

https://www.euromotoelectrics.com/searchresults.asp?Search=Crankcase+vent+hose&Submit=

Have fun at the Rally!

 

[weiner]

Lee, Thanks for your response with good information. I value your opinion. You even helped me several years ago when one of the repair manuals mislabeled 2 of the relays on my Kbike! The Z crankcase breather hose, I've had to replace a few times and even keep a spare which probably should be in the bike with my other spares.

I feel it's important for me to be at this rally since I signed up with the Vintage Club for the vintage display “History of the past 100 years”. I was one of only 3 Kbikes that signed up. I didn't want to be an embarrassment for Kbike community if I got to the rally and had a problem/issue. I feel like the early Kbike is the 'red headed stepchild' in many BMW circles but it is without a doubt one of my all time favorite BMWs even though I have 4 Rbikes! I've spent a couple days removing after-market seat, shock, rear rack and extra lights and replacing with original shock and hardened foam original seat. It should look like the day it came off the showroom floor when I bought it!

Thanks again,
Weiner

 

[98lee]

Weiner,

Have fun!

 

[pglaves]

See you there!