I've read a few posts talking about an o-ring in the carb intake. I didn't recall ever seeing one in there. I just took the carb off to check it and there wasn't one in there. So I put one in. Doesn't seem to be making any noticeable difference.
Update. It's been a while since I've taken the bike out with the cold temps. Today the high was a balmy 44, so I went for a short jaunt. On my last ride I had leaned the c clip up one notch and it made no difference from being on the middle notch. After that I moved it down so that it was one notch richer than originally. Today was the first test at this setting. It was so much better. It barely stuttered when I hit the gas and it revved right up. No warm up or anything. It just started and went. Now I really wish it was nice out. I finally got it all tuned right and I'm putting it away for winter. I ran the carb dry in case I truly don't run it anymore till next year. I hate winter. It's cold and dark. It's 5 o'clock and the sky is pink. Sunset.