How Many $2000 O Rings?

[carockwell]

How many people have done the oil filter canister depth measurement only to find out that their white oil filter O rings were improperly spaced? Mine was WAY off with a canister depth of .180 inches. This means that I needed FIVE shims to get the O ring compressed correctly to .121 inches. Not good for the bearings! By the way, my oil pressure light would always go out and stay out as soon as the engine cranked over.

[RandyB]

Now you're really scaring me. I chickened out on changing my filter the last time after reading Snowbum's articles. Anybody have any advice? Or is this really not a big deal?

[flash412]

Now you're really scaring me. I chickened out on changing my filter the last time after reading Snowbum's articles.What on earth makes you think the dealer gives a half a hoot? You pay him to do the least work possible because that's how he makes the most profit.

[cjack]

Now you're really scaring me. I chickened out on changing my filter the last time after reading Snowbum's articles. Anybody have any advice? Or is this really not a big deal?

You just have to be careful. Look at the old o ring and if it looks like it has a good squeeze on it then just replace it and the shim, etc. Be careful to make sure everything stays where you want it...lay on the floor and watch as you put it all back, etc.
Most of us changed filter after filter this way before we knew we were supposed to worry.

[Boxerkuh]

I can't say that I ever measured it. The only thing that I always remember is that it is a pain is in the a** to get all the washers, shims and O Rings in place before getting one of the screws started. Now again I only change the filter every 5K, but then again, I also ride about daily.... :brad

[BubbaZanetti]

what was the design cocnept behind this filter, were they attempting to protect it by putting it inside the engine casing??? i never had a problem, but the 2K articles did worry me for a while, and i also think i was putting the shim on the wrong side of the o-ring for a bit.............

[James.A]

Early airheads are immune.

[cjack]

Early airheads are immune.

The interesting thing is that the BMW parts fiche (ETK) does not acknowlege the earlier, bullet proof, bolt, cover and plate with paper gasket. I forget when it changed, maybe '74, but it was in anticipation of the oil cooler I guess.

[carockwell]

Just did a 40 mile ride after getting the O ring properly spaced. I definitely notice that the engine runs smoother from 2500-3500 rpm. Before I always kept the motor at, or over 3500 rpm. That probably saved it. After I put another 1000 miles on it I will check the oil filter for contaminants again. If it comes out okay I 'll be the lucky winner and I won't need to do the bearings until I need top end work. If the filter shows some more bearing crap, then its another rebuild... It seems that the bikes may be pretty tolerant of incorrect O ring spacing, but they need to have the metal shim placed against the cannister to protect the O ring from getting cut. If the O ring gets cut the motor loses oil pressure before the next filter change.

[cjack]

How many people have done the oil filter canister depth measurement only to find out that their white oil filter O rings were improperly spaced? Mine was WAY off with a canister depth of .180 inches. This means that I needed FIVE shims to get the O ring compressed correctly to .121 inches. Not good for the bearings! By the way, my oil pressure light would always go out and stay out as soon as the engine cranked over.

And I take it you were not using the paper gasket and are not now.

So I forget, did Oak ever say what you could do about proper spacing? Other than shims? I guess if I had this kind of spacing, I would hve a thick shim made.

[RandyB]

The interesting thing is that the BMW parts fiche (ETK) does not acknowlege the earlier, bullet proof, bolt, cover and plate with paper gasket. I forget when it changed, maybe '74, but it was in anticipation of the oil cooler I guess.

From what I've read, the oil cooler almost seems like a complicated afterthought. I've never found anyone who recommends removing it though. Judging from the thread on the screw used to open the thermostat, there doesn't seem to be much agreement on it.

I pulled the lower fairings and studied the thermostat, drawings, etc. and have it pretty well figured out. I'll try the reverse engineering approach, backed up with the manuals. It's only money....

[cjack]

From what I've read, the oil cooler almost seems like a complicated afterthought. I've never found anyone who recommends removing it though. Judging from the thread on the screw used to open the thermostat, there doesn't seem to be much agreement on it.

I pulled the lower fairings and studied the thermostat, drawings, etc. and have it pretty well figured out. I'll try the reverse engineering approach, backed up with the manuals. It's only money....

Oak says you need a cooler on those bikes. I never worried about draining the cooler.

[jmerlino]

Now you're really scaring me. I chickened out on changing my filter the last time after reading Snowbum's articles. Anybody have any advice? Or is this really not a big deal?
I ended up redoing my last filter change after reading the article, and discovered that like Bubba, I had put the shim on the wrong side of the o-ring. I haven't measured the clearance, but the o-ring seems to get pretty good compression when I screw the thermo down.

[carockwell]

The shims are the only easy way I know of to get the proper compression. If you really did not like using multiple shims, then I think machining a thick spacer would not be an improvement. The thin shims can easily conform to any canister surface, where a thick spacer might leave a gap. I doubt that either solution would be a poor choice.

No matter how far off your canister depth, it will always "feel" like you are compressing the O ring. This is because you ARE compressing the outside radius of the O ring when you bolt the cover on.

Apparently there are enough airhead bikes with incorrect canister depths that everybody should attempt to get theirs measured and set the O ring space to .118-.126 inches. Obviously many owners have run their bikes with incorrect values for a considerable time, but good oil pressure is worth a little sacrifice.

[Bob_M]

From what I've read, the oil cooler almost seems like a complicated afterthought. I've never found anyone who recommends removing it though...
My 84 R100 did not come with an oil cooler. I bought one and installed it and after a couple of oil changes took it off. There are no performance modifications on the bike, only an S fairing so nothing blocks the airflow over the engine. It runs nice and cool with nary a problem.
:wave

[James.A]

There is no place to utilize the O-ring in a /5 or /6. When I used to order filters from Capital Cycle, I was always puzzled as to where the O-ring and big flat washer were supposed to fit. In the early airheads, the tube in the center of the oil filter canister is threaded in the end and a cap is held in place by a bolt. When the sump is properly filled, the level comes up to the bottom of the cover opening. The cover and paper gasket simply impede the sloshing motor oil from dribbling out. I would think that anyone with a threaded center tube could retro-fit the primitive design. /7's are the point of the E.O. change regarding filter cover, the O-ring, and spacer. BTW, I'm still using an old-fashioned, printed parts book. The only alternative filter center tube indicated in my book is for the R100RS with the oil cooler.

[James.A]

The interesting thing is that the BMW parts fiche (ETK) does not acknowlege the earlier, bullet proof, bolt, cover and plate with paper gasket. I forget when it changed, maybe '74, but it was in anticipation of the oil cooler I guess.

Parts numbers from 1980 parts book as follows;
cover-11 42 1 250 282
gasket-11 42 1 250 284
bolt- 07 11 9 911 631
inner filter cover-11 42 1 251 300

[cjack]

Parts numbers from 1980 parts book as follows;
cover-11 42 1 250 282
gasket-11 42 1 250 284
bolt- 07 11 9 911 631
inner filter cover-11 42 1 251 300

I see it now. I had to go to Mobile Tradition.

[1505]

I just read all this on the filter change and still am confused as to which side the spacer goes on. Does it go next to the block or next to the cap?

Ray #1505

[cjack]

I just read all this on the filter change and still am confused as to which side the spacer goes on. Does it go next to the block or next to the cap?

Ray #1505

The shim or spacer is between the o ring and the "block", which is actually the filter can to protect the o ring from the filter can edge. The filter can edge was softened later to solve this problem. It could be, however, that the shim is good to squeeze the o ring a bit more anyway.

[RandyB]

Well I changed the oil, filter and drained the cooler. Not as bad as I'd imagined, thanks to the replies on this thread. :) I didn't use the refill bolt on the cooler, just idled then rode gently until it opened. So far, so good. I doubt I'll drain the cooler again. Doesn't seem to be worth the trouble. Using the hinged filter, I was able to change it without removing the pipes.

I was told that the thermostat wouldn't open unless it was very hot and I was idling in traffic. Maybe, but mine opened somewhere on the ride home (40 miles) in about 60 degree weather if the temperature of the oil coming out of the hoses was any indication. The more I mess with the airhead, the better I like it. Maybe an R75/5 next. :clap

[James.A]

Maybe an R75/5 next. :clap
DO NOT, under any circumstances, buy an R75/5. The crazy-stupid simplicity will ruin you.

[PeoriaMac]

DO NOT, under any circumstances, buy an R75/5. The crazy-stupid simplicity will ruin you.

But....don't you have a couple of them???

[TZOLK]

So how many miles are we talking to lack of lube damage to the camshafts and rod ends if the o-ring isnt skavished enough. I just finished an oil change. It has the smoothened canister edge on it. I put 2 shims on it this time, usually use only one. it measured 3.25mm or so without shims. Have put 10k on it in 2 years , only used 1 shim. at one time i used a gasket also, but no more. still tickin. i looked at the gap between the canister and engine and it was minute if at all. i didnt try to fit a feeler guage in there, shoulda. So, shoulda the engine have ground to a halt in the last 5k or 10k if things werent tight? It has 46k on it and i know the last owner only used 1 shim.

[20774]

Todd -

According to the methods proposed by Oak, you're getting about 33% compression on the o-ring. His recommendation was more like 10-25%. If you dropped one of the shims, the compression would be about 26%...a little better. I'd be afraid that too much compression will deform the o-ring too much, thereby opening a gap and allowing some oil to bypass the filter. You squeeze on the o-ring, it's got to go somewhere...

Kurt in S.A.

[James.A]

But....don't you have a couple of them???
Yes Mac,.....I am ruined.
Todd, If you had a motor lubrication problem, you would surely know about it at 46K.

[TZOLK]

Jim, first of all , you Are a winner in my book.
Secondly, well I took apart the goods again tonight and found out that the canister was about 4mm away. .151" and the oring is .1575 thick. Thats not much compression even with one spacer. So I kept the two spacers in. They were .012" thick each. with the spacers and o-ring seated in, the oring came out about .52mm from the outer surface. The cover went on good, not hard at all. At one point in time I had on one shim, oring and gasket. The oil has been overchanged also with filters. Last filter element was clean.
I measured the gap between the canister and the engine and the crack is .008"

With so little room for error and high probability for mass destruction im suprised there isnt(was) an epidemic of blown engines. How many people have actually destroyed their engines due to this one senario. Makes me go crazy!

[20774]

With the cannister depth of 4mm (as opposed to the 3.25mm value before), and using 2 shims, your oring compression is about 15%...that's a reasonable number. 1 shim only gets you about 8% compression...probably not good. Two is the way to go...

Kurt in S.A.

[TZOLK]

With the cannister depth of 4mm (as opposed to the 3.25mm value before), and using 2 shims, your oring compression is about 15%...that's a reasonable number. 1 shim only gets you about 8% compression...probably not good. Two is the way to go...

Kurt in S.A.


Cool, my first measurements were way off. I think my past gasket useage also would have resulted in bad things but so far so good. Havent torn it apart to measure the con rod big ends or anything else but it does run good. I cant believe the can is set so far back. Is this adjustable? I cant believe BMW would have made a mistake like that.
Do you guys know anyone who has suffered as a result of this?

[RandyB]

DO NOT, under any circumstances, buy an R75/5. The crazy-stupid simplicity will ruin you.
About everything I've read indicates it's the best of the airheads. Considering I'm about as simple as a sledgehammer, this may be the bike for me. Opinons? On the bike, not my simpleness.... :brow

[James.A]

The only shortcoming of the /5 is the absense of a kill switch on the handlebar. The /6 is a great bike also, but I like the combination instrument set in the headlight and the 4 speed transmission of the /5's better than the /6 set-up.

[bearsfolks]

I got the order of the O-ring and shim mixed up during an oil change. With my wife on the back we got on the freeway and were going about 70 for a mile or two when the bike started to lose power. I pulled off the road and the motor died. When I pulled out the dipstick I got smoke coming out of the fill hole. I trailered the bike to a small independent mechanic in Ceres and he tore it down. The only damage was to the rod bearings. He replaced the bearings and put it back together. Almost 10,000 miles later It's still running fine with good oil pressure and no funny noises. I pulled the pan 6 months after repairs and found no debris. I attribute my good fortune to Syntec synthetic oil. I had no damage to the bores, the rings or the main bearings. I'm lucky I guess, but now I always have the service manual out when I change the oil and filter.