2011 EC 125 Clutch slave problem

[MCP540]

Hey guys first post, but looks like ya have these things figured out, so I feel like I'm in the right spot.

Just picked up my wife a 2011 EC 125 a few weeks back, bought it knowing something was up with the clutch, but seems to be possibly be deeper then I first thought. Please excuse me if I use the wrong terminology, but the slave cylinder has a O-ring around the piston, this O-ring is proving to be hard to find a exact match in size. I have gotten close but the problem is, it acts like the piston is having to travel to far out of the cylinder and hangs the O-ring when being pushed back in. Sort of like the plunger rod may be to short. I have found online where someone had the same problem on the same bike, but never said how or if it was fixed. I have also found a GG replacement O-ring and piston kit, but at $75 I want to make sure it want do the same thing when I put it in. Also am using EDPM rings, so no swelling should be occurring. You can put the O-ring back in place a ride a bit then it will pinch again and lose all pedal on the lever. Anybody have similar problems or remedies?


Thanks in advance!

Cody