'81, all stock clutch. No problems riding, seems completely normal. But...today I was on the top of a hill and for fun I thought I'd coast down it and pop the clutch to start the bike. Popped it in 2nd and couldn't feel the engine turning, or even a jolt. Pulled in the clutch and put it in 1st, and tried it again. Same thing. Did recently switch to GTX 20w50 when I couldn't find my regular brand. And again, riding seems normal. Had the engine apart a couple years ago and didn't measure the plates but didn't notice anything unusual about them.