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

[PlecoLB]

Except for the wear on both ends of the conrods, the wear is surprisingly low on the rest of the motor.

Not sure why the conrod bearings should be more prone to damage.The main bearings look like they had some impact damage. There are some small indentations, as can be seen in the one pic.



The Oil issue, is more of a cold versus hot climate issue for me. At our mild to very hot temps, a 20W40 or 50 would be better. At freezing temps a 10W would be a better bet, as the startup lubrication is much better. But it would probably get way too thin at 40 deg c heat out in the bush over here.

I am still cleaning up, and will keep it posted.

[ragtoplvr]

Detonation, severe spark knock can stretch the big end of rods enough to cause a bearing to spin. So can severe lugging, maybe with detonation however the pistons show no sign of damage do they. Erosion of top ring groove is common under these conditions. Were any rings broken?

More likely it was on its side too long running.
Or blew out a sight glass and lost oil before it was noticed.

Lack of ZDDP would cause pitting on the cam shaft, lifters, push rods, etc. It has no effect on plain bearings at all.

Rod

[def]

Originally Posted by PlecoLB

Except for the wear on both ends of the conrods, the wear is surprisingly low on the rest of the motor.

Not sure why the conrod bearings should be more prone to damage.The main bearings look like they had some impact damage. There are some small indentations, as can be seen in the one pic.



The Oil issue, is more of a cold versus hot climate issue for me. At our mild to very hot temps, a 20W40 or 50 would be better. At freezing temps a 10W would be a better bet, as the startup lubrication is much better. But it would probably get way too thin at 40 deg c heat out in the bush over here.

I am still cleaning up, and will keep it posted.

Are those solids (debris) I see in the oil channel on that main bearing insert between the two lube oil ports?

[PlecoLB]

Not sure. Cleaned it up without noticing. The pics come out so clear that I notice things afterwards only.
I did however find small flakes of metal and brass from the big ends in the sump part of the motor.

[PlecoLB]

OK, here is some history on the previous owner.

She rode this bike mostly long distance off tar routes. Although she used the bike past its offroad potential some times, she never over revved wheelied etc. But the bike was properly utilized.

Althought she is a girl, she can ride! A picture is worth a thousand words:

[Wy'east]

Well at-least she was having fun and the bike wasn't a hangar-queen.

[PlecoLB]

OK< I finally managed to get all the parts together, and I am busy re assembling the lot.

Some notes on buying parts. This would probably apply to most makes.

1. Take the manual and go through each page to get what you need
2. Even then you will probably not get everything. Allow for some extra time.
3. BMW took about 3 weeks to source the parts locally. With constant reminders from me.
4. I decided to add the conrods to the crank, and found out that only 2 bearing shells were supplied. BMW only supplies 1 shell per box, and not 2 as per everybody else.
5. I got lucky and got 2 shells from the other local BMW shop. Luckily I took the sample box, as the were going to supply me with roller bearings to fit as big ends. As the guy gave me the correct bearings, he asked how I decided to get the "red" shells. I asked what do you mean red shells. Did not know there were different colours. He said there were blue ones as well. My next question was the obvious, "what is the difference?" His answer was the obvious " Don't know" . So I called the previous shop which I gave my VIN number to, to try and find out why they got me the red bearings. His obvious answer: "I told him I wanted the red ones, as I saw the red colouring on my old bearings." By now I was seriously worried. I looked up all over Google, and found that the red bearings are standard, and the blue bearings are +0.25mm. All my components measured within original wear limits, but I would have cut the crank if I had known.
6. If the manual says "DO NOT re use bolts" then do not re use bolts. Like the conrod bolts. It says so clearly in the manual. Unfortunately I did not read that far during the dismantling, but I read that on the assembly. Needless to say, that both dealerships that provided me big end bearings failed to mention this. Now I am without these and have to carry on until after the weekend. I called, and the are only available ex JHB, and possibly 2 days. Luckily You can do the conrods after the motor is back in the bike.
7. So, the parts are expensive due to the cost of stock keeping. But do not expect to see any stock at your local dealership. Even when you sit with the parts salesman and go through the manual, do not expect to get all the parts you need. And do not expect them to guide you.
8. May faith in dealerships took a further knock with this. I could only imagine the mechanic starting the assembly, and seeing he did not have the conrod bolts, just using the old ones. This would have resulted in an exploding motor about 5000kms down the line. Just out of warranty.

[ragtoplvr]

Cracked con rods can not be re-sized when spun. For popular car engines bearings with oversize OD are available to the big re-builders. I vote for engine on its side too long. Lack of ZDDP will not cause bearing failure. This was not due to non-motorcycle oil. .That would be early wear of the cams and lifters.

Rod

[Pekkavee]

Originally Posted by PlecoLB

OK< I finally managed to get all the parts together, and I am busy re assembling the lot.

Some notes on buying parts. This would probably apply to most makes.
5. By now I was seriously worried. I looked up all over Google, and found that the red bearings are standard, and the blue bearings are +0.25mm. All my components measured within original wear limits, but I would have cut the crank if I had known.

Are you sure about that? Red and blue. BMW Max Fiche says red is cover side and blue is rod side. Only the part number tells which are +0,25 mm. http://www.maxbmwmotorcycles.com/fic...6&rnd=08102012 Engine picture #11_2806 Pekka

[PlecoLB]

Some pics through to current stage.

Sorry about the quality. It was bright outside, stuffing up the backlighting.

Box of spares. About a shoebox full.



Damage to the wallet. About $850 USD.



Biggest of the many pieces of welding slag found when cleaning the casings. (one corner was welded where bashplate came off)











Gearbox added:

[PlecoLB]

Originally Posted by Pekkavee

Are you sure about that? Red and blue. BMW Max Fiche says red is cover side and blue is rod side. Only the part number tells which are +0,25 mm. http://www.maxbmwmotorcycles.com/fic...6&rnd=08102012 Engine picture #11_2806 Pekka

You'll give me a heart attack here.

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

[Pekkavee]

Originally Posted by PlecoLB

You'll give me a heart attack here.

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.

03	11 24 7 700 603	BEARING SHELL, COVER SIDE, RED	0.04	2	$26.27
03	11 24 7 700 604	BEARING SHELL, ROD SIDE, BLUE	0.04	2	$26.27
03	11 24 7 700 605	BEARING SHELL, COVER SIDE, RED - +0,25	0.04	2	$26.27
03	11 24 7 700 606	BEARING SHELL, ROD SIDE, BLUE - +0,25	0.04	2	$26.27

Pekka

[PlecoLB]

Originally Posted by Pekkavee

Have a look into BMW Fax Fiche page and picture 11_2806 and part number #03 in the list. I don't know if it's right info there. Pekka

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

I had a look at http://www.bmwmcchattanooga.com/show..._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!!!

[Gerg]

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

[Pekkavee]

Originally Posted by PlecoLB

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

I had a look at http://www.bmwmcchattanooga.com/show..._trimLevel=730
They concur with what you say.
The Fckrs!!!

Happy you didn't get the heart attack.

Pekka