Oil filter cover o-rings

When using oil filters from manufacturers such as EMGO, I have received units containing new o-rings which are the correct diameter but much thicker than the stock o-rings. I have always replaced the rings with stock-sized new ones, but they are getting harder to find. Has anyone used the "thick" ones, and do they work OK? It seems they would not fit completely within the groove in the cover, or maybe be cut when tightening. Thanks for any input!

That's a good question,Vachon.
I've never had a "Thick" o-ring come with any filter before...any way You could take pics of the differences,and post them?
I would think that if it was THAT much thicker,that it would leave a slight gap around the cover,allowing grit to get in there,and chew away at the o-ring,or is it THAT thick?

I've never used the Emgo filters before, so I really can't say if the o-rings included with them are larger than OEM o-rings or not.

I regularly use either STP or Fram filters, and the o-rings that come with them fit spot on!

G'day all,
That's interesting, 'cos the last lot I used had "thin" O rings. As in pretty much dissappeared into the groove, wasn't game to use it. Ended up using the old one again which I'd call a "thick" one, this one was a snug fit in the groove and protruded far enough to look like it would seal (which it has)

I just put a new Fram filter in mine and the o-ring that came with it fit like a charm!

I would use the new one in each case, the thicker one may be a bit softer and therefore it will crush more giving a better seal.
I wouldnt worry about dirt on the outside as long as it dosent leak oil its doing its job

I just used my emgo rings. They are a little thicker, but they do fit and its better off than having a smaller ring since these ones seal better. So don't worry about it.

No need to ever replace the oring unless it's leaking. I wouldn't use the wrong size oring for sure. It's standard aftermarket stategy, probably using the same replacement oring to replace multiple different Kawasaki orings, and worse than that the same filter fits a variety of other bikes like Honda CB750s, Goldwings ect. No doubt the same exact oring was used in all these bikes? No, I don't think. On top of that, no doubt the oring is made in China of course. Don't use them, the filter orings will outlast your motorcycle most likely if never replaced, and what's the worst that could happen? a 2" oil spot on the floor. Now it's time to take 10 minutes and replace the rings.

I use EMGO filters, and I use the o-ring that comes with the filter. I never knew they were different size, but they fit fine, and don't leak.
I'd rather use a new o-ring than re-use the old one. It's easy to change during the filter change, and a pain if you discover that your old o-ring leaks after you're done.

Just for info, not that it matters, but my 1979 KZ1000 still has the original Kaw orings on the filter cover and bolt with 80,000 plus miles. Chance of leaks reusing the oring is slim. All the KZs I've ever owned I only had one leak that I can recall on the filter bolt oring. Another just for info, if the filter or bolt did happen to leak, all you have to do is drop the filter. Yes a cup of oil is going to be lost and a slight mess, but no need to drain the entire oil pan anyway. Kawasaki doesn't include orings with the filters and I could see visually aftermarket were not even close to being right, so threw out any junk orings included with them.