GS First Oil Filter Change

I guess I'm looking for a little hand holding. I've read Snobum's and Anton's info on changing the oil filter for my 1995 R100 GSPD. From what I understand the paper gasket should not be used, just the shim, black and white O rings. But, I found the paper gasket in addition to the shim, black and white O rings when I took it apart today. Should I put it back the way it was with the paper gasket or, not use the paper gasket?

The critical thing that both Snowbum and Anton discuss is knowing the canister depth relative to the outside of the engine case. Nominally, this dimension is 3 to 3.5mm. Generally speaking, for canister depths on this order (and bigger) you shouldn't need a gasket. But for canister depths less than 3mm, you will need a gasket..hopefully no more than that. So, it's important to know this depth measurement.

The gasket is not an oil sealer...the big white o-ring does the sealing of the pressure. What the gasket does is move the cover out to prevent too much pressure from being applied to the o-ring if the canister depth is less than 3mm.

You are aware of the metal shim. Generally it is needed to protect the o-ring from being cut by the sharp edge of the canister. Except, there are versions of the canister introduced at a later time with a rolled edge. Likely your bike has the rolled edge. So, technically, you wouldn't need the shim. However, if your canister is deeper than say 3.5mm, now you do need a shim in order to ensure enough compression on the white o-ring. The shim (and multiple ones if the depth is 4mm and more) is thus a spacer to get the proper compression on the o-ring...not too much but at least some...about 10-25% of its thickness.

So, before you can decide what to do, you need to get a set of digital calipers and measure how far inset the canister is.

Thanks, clear explanation.

Measured the case to canister depth, it is 3.46 mm. Also, the canister edge looks rolled. So technically I should not need the shim or paper gasket. I'm inclined to put in the shim to be safe, will this put too much compression on the white O ring?

According to Anton's website:

http://www.largiader.com/tech/filters/canister.html

for your 3.46 (call it 3.5) he indicates that with the one shim and no gasket, the resulting "groove" is 3.2mm. So the amount of compression is 0.8mm divided by 4.0mm or 20%. This is a decent number...you want somewhere between 15 to 25 or maybe 30%.

Kurt, appreciate the hand holding. All the talk about the $2000 O ring freaked me out.

Actually, on a '95 with 3.5mm I would just use the white O-ring.

The example I provide is potentially misleading if you don't actually read the words: it does not target the same compression that I actually recommend. You have to read everything.