Counter shaft o ring(s) different size than the parts' list says?
 

hello people, I went on to repair my leaky front sprocket on a EC 300 2005. I bought a seal and a couple of o rings (ID 25, 2 mm thick by the parts list). when I took out the old O ring I noticed that it was smaller in ID and thickness, i.e. 23mm and 1,5 respectively. also it was the only o ring in there, I thought there were supposed to be two? anyway I bought two new rings but managed to fit only one with the new circlip barely getting in the groove nice and snug. there seems to be no room for the second ring unless I shorten the sprocket by 1-1,5mm on a lathe to get the second one in and clear the clip groove or deepen the inner step on the sleeve by 1-1,5mm to accommodate both o rings. Is any of those options viable? previous circlip looked a bit worn and possibly didn't push the sprocket deep enough to press the ring and it had a bit of play. Did I do something wrong here? I contacted the mechanic that rebuilt my engine a few months ago and he told me that, indeed, there is only one ring in there... :confused: The ones that the parts list commands (25X2) don't fit in the step of the metal sleeve but the smaller ones (23X1,5) go like a charm and seal well on the shaft but as I said before, only one of them went in... :o should I put both in and really struggle to put the clip?
Is there a chance some models use different size o-rings?
So did I f*** up or am I in the clear? :D

many thanks in advance.

I have replaced by 03 + O2 at least twice each and they indeed have to 2 O-rings I do not know the size of the O-rings cuz I got them from the dealer. Sometimes one gets stuck down in the engine that you have to dig out. It's also been my experience that if you don't replace the sleeve it would start leaking quickly. There should be a little bit of play for the snap ring to go in from shouldn't have to push the sprocket down

I looked for the second o ring around the shaft but to my amazement there was none. also the sleeve didn't look worn, just two lines of discolouration where the seal seals but no grooves.

gg changed the seal/ oring size in 05 but didnt change it in the parts book look at a latter parts book

I downloaded EVERY EC 250/300 manual from 2000 up to 2019 and none of them says any different size from 25X2 (2 orings). As long as it doesn't leak it makes no difference to me but I am perplexed about it. I haven't had the chance to ride it properly after the fix, just a few km's from the shop to the garage and no leaks occurred so far.
I wonder if any fellow gasgas rider had the same problem?

Update: I had a good 4-hour ride today in mostly rocky terrain and I saw NO leaks from the shaft. Everything is clean down there. :D So it seems that it takes one o-ring. (?)
my guess is that the worn circlip was the reason for leaking since it allowed some axial play for the sprocket and possibly the sleeve.