My mentor and motomech friend, Mike and I tore into the k100RS this weekend. This is what we found.

The bike runs great, Compression was 138, 137, 138, 139. Number two plug was hot and white colored with Zero to very low resistance. The plug wires had normal resistance readings back to the Alternator. (NGK7). We figured it was a bad plug? We let the oil heat up a little and we drained and flushed the case, let the oil sit for a few hours, then carefully poured it out until we found GOLD very fine bronze silt (not much) . And a few pieces of silver colored non magnetic metal that were alarmingly large. Say .5mm in Dia. maybe 7 pieces. Mike was worried about the crank bearings.

Here is the background of the blue RS. It was owned for 25 years from a gentleman who died. And I am guessing that it wasn't serviced nor ridden in the later part of his life. His Heir and son-in-law just took it in and got it running and rode her hard for two years. Mileage is 13,000. It looks pretty clean,but it must have tipped over at one point because mirror was missing, vent fins on knee fairing was slightly cracked scratch on tank under fairing on same side, side of tail light cracked, top case was missing mounting plate and road rash gouge on port side aft top corner...all on same Port side. Son-n-law changed diff oil and bought a new battery. Sold it to me. We found some strange things:

1. brake fluid on top of the aft diaphram of the resevoir. Checked diaphram for holes there were none. We think Son-n-law didn't know how to add fluid. We are flushing out the front and back brakes with new fluid.

2. Bike came with two sets of panniers. One set that was on the bike had rectangular flat key covers and uses the flat old key. The Son-n-law did not know there were keys for this . The other set was in less oxidized condition and had round cylinder latches that matched the ignition key, but there was a light scuff on the Port pannier and there was aforementioned top case damage (thanks to TWB for sending me the key and to another forum member for locating the mounting bracket for the topcase). Son-in-law (SIL) did not know that the keys were for the ignition. SIL also gave me two sets of brake pads. One new and one set almost new. Very strange. By the condition of the panniers and his lack of knowledge, I would say that this minor fall happened long before Son-in-law owned it.

3. When idling the amperage was low. 11.6 amp at idle at 3000rpm it was 13.5 It seems strange that the alternator would be bad, I told Mike to make sure all connections were clean and dielectricly lubed(don't use dielectric lube, except as noted on subsequent posts, thanks for the correction) Does this sound like a likely culprit? The motor and bike is very clean.

4. The motor oil was very dirty. with these metal filings and pieces as described above. Does this sound possible? What could it be. Our course of action is to change oil and filter, with Castrol Synthetic and BMW filter and do another change in three months, and check what we find. This has me a little concerned. When we get her cleaned up and run her we will review oil again soon.

5. We did have oil leaking out of the oil filter cover cap.

6. Front fork seals are leaking slightly. Rebuilding and will get Gators.

I will post the bad pics of the oil if I can find out how to download photos onto this forum. Do I push "host images" icon? Must I download another file to be able to browse images from my PC? Sorry for the dumb questions.

thank you all in advance.

I think I figured out the image thing.

This should be the fragments in the oil. Hard to see from the I phone, in fact the bloch is the reflection of my thumb and phone. The largest fragment is .5mm.

UJ

With regards the metalic debris I would not be too concerned and give it an oil change then drain in about 1000miles and check again.
Better having it in the oil that comes out than up where it does damage.
You don't say which model the RS is 8v or 16v. ( good idea is to put it in the signature line so it always shows) The compression is good for an 8v but a bit down for a 16v but still ok
Plugs should be D7EA for 8v and DR7EA for 16v. If one is very white then suspect an air leak to that cylinder, usually after the injectors. Its a good idea to remove all the intake bits and reassemble carefully making sure there are no air leaks from the filter onward.
If you want to inspect the bottom end bearings it is as easy as removing the right side engine cover and the crank is right in front of you.
Sounds like the SIL is a real goose fancy putting the fluid on top of the rubber membrane.

Thank you Rick. I appreciate it.



UJ

Hi UJ,
No No he said holding up his cross and invoking the most potent prayers he knows to exorcise the evil of dielectric grease on conductors. Seriously the only place to use dielectric grease or silicone grease as it is called is on the rubber boots inside spark plug caps and on injector O rings never on electrical contacts. The best stuff to use is DeoxIT made by Caig in the USA and available in most parts of the world, use the G first and then the S.

Always worth putting a couple of high temperature super magnets onto the outside of the oil filter so that any magnetic particles inside stick to the inside of the filter case and any going by on the outside stick to the outside. That won't help with bronze particles but at least will get the magnetic ones.

The output of 11.6 at idle is volts not amps and 13.5 volts not amps at 3000 is just fine and dandy, it is worth taking the voltage regulator brush pack out of the alternator to check the length of the brushes but at the moment don't worry about that output, all older vintage K's actually slowly flatten the battery at idle.
Regards,
K-BIKE

Thank you Kbike.

uj

http://www.ebay.com/itm/BMW-K100-RS-Belly-pan-with-mounting-bracket-/160957056444?_trksid=p2047675.l2557&ssPageName=STRK%3AMEWAX%3AIT&autorefresh=true&nma=true&si=VWNRczQFEiLCAy9ZgtRxawKQ2oI%253D&orig_cvip=true&rt=nc

No contenders, but I thought it was a great deal.

UJ

There is a lot of stuff in US ebay that I would buy but for the extortion thats called postage to Australia.

I will offer an explanation for the "bits in the oil".I may be ridiculed but here goes. As the bike has only got 13,000 miles on it,could these bits be from the running in process. I have been told that the run in period is much longer than say jap bikes as the tolerances are not as accurate on the BM's.

GMcQ

When I worked for Honda Australia we were required to do oil filter inspections at times and even after 20,000k we would still be finding small bits of alloy in the filters that had been hiding in some corner and eventually got washed out.
We used to open the filter and pull it to bits and wash out all the particles then dry the sludge and weigh the crud, All the results were sent back to Honda with written reports that they actually read, they were and still are very active with after sales and warranty inspections etc. I have been involved with Suzuki and Kawasaki as well and Honda is streets in front in that aspect.

gmcq wrote:I will offer an explanation for the "bits in the oil".I may be ridiculed but here goes. As the bike has only got 13,000 miles on it,could these bits be from the running in process. I have been told that the run in period is much longer than say jap bikes as the tolerances are not as accurate on the BM's.

GMcQ

Thank you GMcQ, that is a very viable idea. I propose that the oil may have been changed cold, and that the "running in" or as we gringos say, "breaking in", and perhaps not changed often enough, and sitting for a long while and then perhaps the son-in-law jumpin on her (WHOOPY and YEHAW). This may not have been how the dear old deceased Kmeister may have ridden her. So this may have loosened heretofor flotsum and jetsum in the oil. So I like your explanation and it is a likely possibility.

UJ