Rattle noise at about 4000RPM while coasting. (found the source)

You'll give me a heart attack here. :eek1

Anybody else with info? The BMW guy here supplied me standard bearings, which according to him is red.

Sorry about that.
Have a look into BMW Max Fiche page and picture 11_2806 and part number #03 in the list. I don't know if it's right info there.
<table cellpadding="0" cellspacing="0"><tbody><tr style="vertical-align: middle; font-family: Arial; font-size: 11px; background-color: #ddd;"><td style="width: 17px; border-bottom: solid 1px #666;" align="center">03</td><td style="width: 85px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-weight: bold;" align="left"> 11 24 7 700 603</td><td style="width: 265px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-family: Arial Narrow;" align="left"> BEARING SHELL, COVER SIDE, RED</td><td style="width: 30px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">0.04 </td><td style="width: 35px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">2 </td><td style="border-left: solid 1px #ddd; border-bottom: solid 1px #666; width: 70px;" align="right">$26.27</td></tr><tr style="vertical-align: middle; font-family: Arial; font-size: 11px; background-color: #fff;"><td style="width: 17px; border-bottom: solid 1px #666;" align="center">03</td><td style="width: 85px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-weight: bold;" align="left"> 11 24 7 700 604</td><td style="width: 265px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-family: Arial Narrow;" align="left"> BEARING SHELL, ROD SIDE, BLUE</td><td style="width: 30px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">0.04 </td><td style="width: 35px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">2 </td><td style="border-left: solid 1px #ddd; border-bottom: solid 1px #666; width: 70px;" align="right">$26.27</td></tr><tr style="vertical-align: middle; font-family: Arial; font-size: 11px; background-color: #ddd;"><td style="width: 17px; border-bottom: solid 1px #666;" align="center">03</td><td style="width: 85px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-weight: bold;" align="left"> 11 24 7 700 605</td><td style="width: 265px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-family: Arial Narrow;" align="left"> BEARING SHELL, COVER SIDE, RED - +0,25</td><td style="width: 30px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">0.04 </td><td style="width: 35px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">2 </td><td style="border-left: solid 1px #ddd; border-bottom: solid 1px #666; width: 70px;" align="right">$26.27</td></tr><tr style="vertical-align: middle; font-family: Arial; font-size: 11px; background-color: #fff;"><td style="width: 17px; border-bottom: solid 1px #666;" align="center">03</td><td style="width: 85px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-weight: bold;" align="left"> 11 24 7 700 606</td><td style="width: 265px; border-left: solid 1px #ddd; border-bottom: solid 1px #666; font-family: Arial Narrow;" align="left"> BEARING SHELL, ROD SIDE, BLUE - +0,25</td><td style="width: 30px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">0.04 </td><td style="width: 35px; border-left: solid 1px #ddd; border-bottom: solid 1px #666;" align="right">2 </td><td style="border-left: solid 1px #ddd; border-bottom: solid 1px #666; width: 70px;" align="right">$26.27</td></tr></tbody></table>
Pekka

Pekka, I think you just saved me a lot of money.

I had a look at http://www.bmwmcchattanooga.com/sho...y=20146&ukey_driveLine=123&ukey_trimLevel=730

They concur with what you say.

The BMW parts guys are now in a bit of a spin. I gave them both an ear full. But now I am seriously worried about the main bearings and the rest of the suppliedc parts! The Fckrs!!!

That slag gives you a hint. I suspect there was enough of that in the engine to sand away a lot of parts. Probably where the wear marks came from in the oil pump. I don't think the cases were split to do the repair/welding.

Gerg

Happy you didn't get the heart attack.

Pekka
:eek1:eek1:eek1

Might have tomorrow. Seeing dealer principal. At this point I want to kick over the display bikes.

:eek1:eek1:eek1

"Danger Will Smith....leave the area immediately and seek professional help"

Motorcycle shop parts guys are often clueless, especially young ones....

When dealing with parts people, I trust only the ones with long hair, missing teeth and their not having to look up the part numbers. They know the parts by heart or at least know how to find the correct ones. Once when at a BMW parts counter, I asked for spark plugs for my BMW boxer engine. The parts guy said, "Sorry, we're out of that item. Go to your local auto parts store and get Autolite 3923s. They work just as well and cost $1.50 each."

When I last visited a BMW parts counter (several years ago), I had to view the parts fiche myself and tell the parts man the part number. Even after that, he brought me the incorrect part. Beware...many parts guys have little understanding of parts, where they go, what they do and which ones are correct.

Problem is that this dealership has been around for a while. The other dealership's parts salesman also seemed clueless.

Hearing the mechanic in the background say "The main bearings should be right" made me almost glad
That I am rebuilding this motor myself. Problem is that I cannot ask the professionals for any guidance or assistance as they seem clueless.

Should we now steer clear of anything out of motorplan?

OK, I am back on the rebuild. I was away working in Tanzania for 2 months, and while I was away, my big end bearings and conrod bolts arrived at BMW at least.

I put the new rings on the pistons, and by comparing the old rings, the 150k kms of the motor can be seen.

Here is the old top ring:



And the new ring. You can see the ring gap difference:



The ring gap on the new ring is spot on, again confirming that the sleeve has basically no wear.

Getting the piston into the sleeve was a little difficult without a ring compressor, but with a bit of patience I got that done.



Head and sleeve back on:



Cam chain back in and lined up:



PLEASE NOTE: After assembling the lot, the left cam gear went on without any hassle. But when I tried to fit the righthand side one, the chain all of a sudden came up 10mm short. I knew I had a kink somewhere, but could not see it. No amount of turning the motor out could get the chain shortened. I called an independant BMW mechanic, which was very unsympathetic, as I did not have the motor done by him, and he told me that the kink gets caught between the gear and the back of the bottom chain slide. The only way to get the kink out, was to strip the motor again :eek1. I looked down the chain, and saw the kink there. The chain makes a little hump, with one link standing at 45 deg and the gear and slide had this caught in that spot, simply rolling it along like a little wave as you turn the motor over.

I took it to a more sympathetic indie dealer, but after 2 hours of trying a lot of different things, he got to the same verdict. My heart sank into my shoes, and I felt like saying F@CK.

I took the bike to my good old buddy Mark. He prodded around in there a bit, then took a large cable tie and fed it in between the gear inside the motor and the cam chain while I slowly turn the motor over. We turned the cable tie all around, until it got under the kink in the chain, and then pulled the chain hard on the top, causing it to slip all the teeth and pull the kink out.

If the bloke was not so ugly, I could have kissed him.

If the above does not make a lot of sense, I will try and sketch it. But please make sure that the timing chain is smooth around the inside gears before you assemble the motor and put the whole thing back in the bike.

I will try and finish the bike now, and then that dreaded first start will be coming up.:eek1

Pleco, as you are aware, not many of these engines are disassembled to this level. Therefore, your details and photos are of great value to those who might venture into their boxer engine sometime in the future.

As for parts, years ago, I bought a damaged R50 boxer that had a cylinder broken off during a crash into a curb. BTW, the owner rode the bike some 20 miles back home with the connecting rod flapping around in the breeze. The rod was bent of course. I took the crankshaft with bent rod to the local BMW dealer in Chicago for an assessment. He said, if I would like to wait he would repair it, about 2 hours time. The crankshaft was one piece with roller bearings. He pressed it apart, straightened the rod and reassembled the rotating assembly noting, "Your journals and bearings are in good shape. That'll be $80.00 please (including the new piston, pin, rings package). He had a used cylinder which I bought for $20.00 after he thoroughly checked it with inside micrometers and gauges. I rode that R50 for years without incident.

Today? No way. Those old BMW dealers are all gone now along with their skill and experience.

I await your final posts as you button everything up and press the start button for the first time.....

Not to be a wet towel, but is your new ring end gap in spec? It looks like it might be tight. Too tight cold and the ring will break when at operating temp. Or I may be seeing an optical illusion from the camera lighting.

Hmmmmm, I loves me some hardcore bike pr0n...

Thanks for the thread and the pics.

Specs for the cap is 0,10-0,30 mm. It looks just right.

Pekka
:eek1:eek1:eek1

As the man said above. Peculiar thing on the BMW is that you cannot buy oversized pistons and rings. You have to buy a piston and sleeve set. So no oversized rings to get things wrong.

But thanks for the heads up. As seen in previous posts the wrong big end bearings supply by bmw was pointed out to me and saved me a lot of headache. My posts are 2fold. One to share, and then also for you guys out there to help double check my work.

Almost there. I am crapping myself for that start though.

There are still some dealers and mechanics around that have the skills and experience. But they are getting fewer and fewer.

It seems that the airheads get torn down and rebuilt on a regular basis by a lot of folks. The airhead community is pretty helpful and encouraging even if you have little mechanical experience. I think the single spark oil heads are some of the finest engines built by BMW and wonder if one day there will be a following and mechanical familiarity like there is with the air heads.

Good luck with the rebuild PlecoLB. I hope the start up is uneventful.

...and since the "why" speculation is running wild, I'd like to throw this in the proceedings: that number in the previous owner's screen - that's racing, right? If that's the case, I think we can safely assume some redline-bouncing action in this engine's past life. There's no way to race without hitting the rev limiter on a regular basis. NTTIAWWT.

That was the Amageza offroad rally. A little tougher but fortunately much shorter than the dakar. No space to race a big bike like that. The lady left me for dead most of the time. I was riding a klr though :)

I can confirm that the previous owner is an excellent rider who will take a bike where many men won't.
Hi mate, sorry to see that you are having such major issues so early into GS ownership. See you on the road soon.
Jorg.

+1 Pleco ... reading your posts and other contributors has been a real education. In the past I disassembled engines with uneducated abandon, now I'm more conservative. I've been putting off a couple smaller projects that I'm now inclined to tackle.

I'm looking forward to the rest of the story.
RB

Thanks Jorg.

We suspected a few issues, so the lady gave me a very good price. Although this was unfortunate, it gave me a chance to go through the whole bike and assess everything. The motor is now back to factory spec. Did not open the gearbox though. Not fixing that aint broke.

Doing the gs911 scan this afternoon then its startup time!