Ok, so I worked on my winter project today (Anton my trusted '91 R100GS PD that I have owned for a little longer than a year) and so far I completed quite a few tasks that I have on my list to get it ready for a ride from Indianapolis to Phoenix.<?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-comfficeffice" /><o></o> <o> </o> I still have to do some paint touch up, the timing chain and a check of the drive shaft and final drive.<o></o> <o> </o> I decided to take the engine out of the frame to make it easier to work on the front of the engine as I get into the timing chain job. All oils had already been drained after the last ride. The only thing I had not done yet in preparation to take the engine out of the frame was to take the oil filter out. I did that and checked the O-ring. When I installed the filter the first time I read a lot on Anton's site and spent way too much time measuring and making sure that I do not make the $3000 O-ring mistake. Well, I did well (Thanks Anton!). The O-ring is flat on both sides and must have done it's job properly.<o></o> <o> </o> When I bought the bike the PO had installed the filter without a shim and with the base gasket. When I took the O-ring out for the first filter change it was suspiciously round... After measuring it myself I found that I was between one or two shims and no base gasket. Back then when I inspected the filter it looked good to me.<o></o> <o> </o> Well, today I inspected the filter that I had installed and found things that I did not want to see. There where silver or white particles in there as well as a goldish flake.<o></o> <o> </o> The timing chain seems to be very sloppy, so I did expect to find some silver shavings. If I am not incorrect the sprockets can loose some silver shavings. What really concerns me is the goldish flake.<o></o> <o> </o> I will try to post some pictures from the filter tomorrow. Do you guys have any idea into what direction I should start to think?<o></o> <o> </o> The engine has 99003 miles on the clock and seems to run well. Aside of the timing chain I have not heard too many weird sounds. Maybe a little bit of a louder tapping from the exhaust valves but I am very confident that the valves are correctly adjusted.<o></o> <o></o> <o> </o> Right now I am a little bit panicked about my ride to Phoenix, but maybe I will just deepen my companionship with Anton before I get on the road.<o></o> <o> </o> I'll be thankful for all input from you guys!<o></o> <o> </o> Bjoern
Goldish flakes are usually big end shells. It's not a big job to get the con rods out to check. I had an issue a few years ago where a seal from a oil cooler cover worked its way into the front oil gallery. The engine wasn't fitted with an oil cooler so I've never figured that one out?? The crank was fine fortunately.
Here are some pictures from my oil filter. I hope you can see something on them. I took them with my phone. Does anybody know what these whitish almost rubberish particles are? And here you see the brass flakes that concern me. Thanks for all your input! Bjoern
I definitely plan on pulling it apart! What is the reason to start with the left cylinder? Should I be concerned about the crank bearings at this point? What color material are they made out of? In case I have to replace the big end shells and the crank has not been reworked, I would only have to order the regular big end shells? Is that correct? Bjoern
Maybe somebody used a little too much hylomar/threebond/yamabond on your cylinder base or oilpan gasket or somewhere where it squeezed into your oil.
That's good advice by BMWrench The white rubbery parts are likely to be the oil filter seal breaking up the oil travels up the front of the engine, feeds the camshaft and then travels on to the front main bearing before feeding the rockers and big end on the left hand cylinder. The rear big end is fed from the rear main bearing. My front big end failed for no apparent reason after a major rebuild. It was only when I was turning the engine over I realised there was no oil feed to the front big end. I pulled the front bearing housing and was amazed to find a piece of rubber pop out. Turned out it was a square seal for an oil cooler cover. There's no oil cooler on the bike so it had obviously been in the crankcase for some time and been missed during the rebuild. Mine had black rubber bits all through the engine and across the filter where the crank had chopped a little bit of rubber every time it rotated. There was also gold coloured flakes from the big end shell across the filter.
Alright, I made a little bit of progress. The engine is out and ready to be worked on, Timing chain job is on the list too. What are your thoughts on the condition of the cam sprocket? When I took the timing cover off I realized that there must have been oil coming out of the breather valve. Any idea aside of a blown gasket what the cause could be? Somebody suggested to change all bearings out since I am that deep into the engine. What are your thoughts? What problems should I expect when I do that (crank out)? Would it be better to only fix what seems to be broken? The rear of the engine seems to be dry. I did the main seal and oil pump O-ring last year. Overall the engine needs some good cleaning. And here is Anton waiting to be put back together. Bjoern
Rather than just buy a timing chain kit I tend to inspect the tensioner blade and guide block, if they aren't worn I done replace then but always replace the crank sprocket along with the chain. A sprocket and chain is just a little more than a complete chain kit. Camshaft sprockets seldom have signs of wear so I only replace if there are signs. What are the marks on the nose of your crank? Looks like the rotors been spinning.
I am actually not as worried about the oil in the breather tube as about the oil around the breather valve. My thought was that the gasket was no longer tight and that oil might have come out on the mating surfaces of the breather cover and the crank case. The one thing that was on my mind though was the blowback from the pistons. I did not make a compression test yet due to a lack of equipment. The engine is burning no oil though which leads me to believe that the rings should still be good. I wanted to get a few more miles out of the top end before I rework it. Finances, finances, finances...
Rob, good catch. I had not realized it yet. I went to look at it and it feels like it is some kind of sticky stuff and not scarring of the crank nose. Tomorrow when I work on the engine I will try to wipe it off. I do know that the rotor had been replaced before due to failure. The rotor seemed to be pretty solidly mounted on the crank when I took it off.
I would definitely agree that the orientation of those holes is pretty weird. I checked pictures of other relief valves and all the holes are pointing downwards. Could that be the source of the oil leak close to the breather valve since it is pointing that direction? What would it have done to the running parts?
So tomorrow morning I will pick up my triple square and then after work I will pull the cylinders starting with the left one and remove the conrods. I cannot wait to see what I will find. I hope that the crank is still ok. I will probably post some pictures later in the evening. Bjoern
Alright here we go. I started by taking the cylinders off and came across a hole just above the chain tensioner that is threaded, but does not seem to be used. Does anybody know what it is for? Then I saw that one of my wrist pins has a feel able scratch pretty much in its middle as you hopefully can see on the picture below. Should I replace it or what are my options? Then I realized that there are scratches on the front push rod of the same cylinder that I cannot explain. The head gasket was installed the right way and I am not sure what it rubbed on. What are my options here? Can I reuse the push rod? And now to the actual areas of interest. I did not wipe the oil off. The journals felt absolutely smooth. Left Right Right from the back Left from the back Left bearing shells Right bearing shells It looks to me like the left bearing shell is starting to show some wear. What are your thoughts? All and any input is welcome. Would you guys pull the crank next or assume that its bearings are good based on the bearing shells or the big ends? Thanks for your help. Bjoern
The hole in the main bearing carrier is for a puller. I'd reuse that wristpin after I polished it a bit. Does the bushing look OK? Those rod journals should not look like that; they should look like a mirror. You can probably polish them with some emery cloth. Buy a bunch of it; those journals are hard. The bearings look surprisingly good. It would be my guess that this motor has been run with dirty oil. So where are the flakes coming from? Since you've eliminated the rod bearings, that leaves the mains, unless the wristpin bushing is badly damaged.
Aha, that sounds like I might have to use it soon!? I could not see anything wrong with the bushing but I will double check tomorrow. I will do that. I think that I will clean the oil off tomorrow and take another picture that I will post. But it will probably be the polishing from what you are saying. What grade emery cloth should I use? Would you reuse the bearings or replace them? Sounds like I have to pull the crank then. Thanks for all your input!