That old Oil filter chestnut again

I am already doing a post the on the way this virus has made me work on my 1986 80 g /s Paris Dakar. While I'm waiting for some parts I thought I would change the oil and filter. I've owned the bike just over a year and covered a couple of thousand miles and was told by the previous owner that it was serviced just before I bought it ( he also gave me me the correct service kit, or so he told me ). . This is the first time for me to touch it.
During this current batch of work I have found out that its capacity has been increased to 1000 cc and it has as an external oil cooler mounted on the right-hand crash bar. So I have a few questions for all you super smart Airhead guys ;

1 . Oil filter that came out is OX36 , there is a white o-ring measuring 4.05 mm on the outside edge of the housing and a square black o-ring measuring 3.96 mm in the cover. Both are nominal measurements taken with a vernier. To buy a replacement is that filter from a 100gs ?

2. The depth of the groove in the front of the oil filter housing is 3.8 mm so am I right in thinking there should be a 4 mm black or white o-ring and one 0.3 mm shim, from the Anton Lagadear chart ?

3. The pipes to and from the the oil filter housing cover to the oil cooler have no bleed valve or anything similar. Firstly do I need to drain all the oil out of the the cooler or leave it in and do I need to prime it at all all.
Many thanks

A few more photos to help

I think of you want to go the whole hog you should measure the canister recess and use that when calculating wether a shim needed. I think the shim also protects the white o ring from getting cut by the canister lip.

Having looked through lots of photographs on the Motobins website I found the oil filter OX36 which is a bendy one, is used with the r100gs PD for 1988 to 1990. And according to the the chart from Anton Lagerbeer ( just could not resist it) then if my oil filter housing has a top groove of of 3.8 mm ,I've gone over the threshold of one shim and need a second one leaving the the resulting groove depth of 3.2 mm. However everything worked well for the past couple of thousand miles with no shims in place . Also a gasket was used to seal the cover, increasing the space by0.45mm . I am not sure I really understand this.

Byron, I can't add much but this I can say that you can put an oil cooler on any model. I have one on my R90S (you have seen). So the fact your 80G/S is now 1000cc is not connected/relevant to the oil cooler, filter to anything else. The oil cooler will drain out and prime by itself. I have a sneaky suspicion the thermostatic type oil cooler has a screw-in gizmo that will empty it for an oil change. I need to get my head round that.

I need to get my head round the shim/o-ring issue, too. I have a complete thermostatic oil cooler set and wondering which bike to fit it too....

Gelandestrasse said:

Byron, I can't add much but this I can say that you can put an oil cooler on any model. I have one on my R90S (you have seen). So the fact your 80G/S is now 1000cc is not connected/relevant to the oil cooler, filter to anything else. The oil cooler will drain out and prime by itself. I have a sneaky suspicion the thermostatic type oil cooler has a screw-in gizmo that will empty it for an oil change. I need to get my head round that.

I need to get my head round the shim/o-ring issue, too. I have a complete thermostatic oil cooler set and wondering which bike to fit it too....

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Why? I removed the cooler from my 100RS to make changing the filter a bit less of a faff. It's not really needed unless you're caught in a traffic jam in the Sahara! I've considered doing that on the 100GS but it's not quite the faff it was on the RS.

As to the shim etc, my habit is to get the bendy filter kit from M/works and replace the items carefully and in exactly the same order as I removed them. It's worked ok so far.

Posh Pete said:

Why? I removed the cooler from my 100RS to make changing the filter a bit less of a faff. It's not really needed unless you're caught in a traffic jam in the Sahara! I've considered doing that on the 100GS but it's not quite the faff it was on the RS.

As to the shim etc, my habit is to get the bendy filter kit from M/works and replace the items carefully and in exactly the same order as I removed them. It's worked ok so far.

Click to expand...

Posh Pete, to answer why, I too have a GS and you agree it’s not faff when changing the filter. I don’t disturb the cooler when I change the filter on the R90S. So for me it’s a pastime to decide where this other one goes. Hope you’re happy with that?

The extra oil in the system can only help when I’m past the redline in top, lap after lap for a whole day at Cadwell.

As for the shim, Byron’s bike is modified and it will pay to learn the right way to do things from first principles. Again, it’s a pastime, but this time it is going to build confidence. Your ‘habit’ approach works fine for standard installations.

Each to his own!

I also get sone reassurance when I can see that the white o ring when removed has been squashed a little.