My 50cc has a bad head gasket so it takes full choke to start cold, but once it's warm, I can cut it on and off with no choke. The only time my bike wouldn't start after riding for a while then taking a break was when the CDI melted on the muffler. I tried for 2 miles to get it started hour maybe. I was one block from home and it fired right up. Check your CDI? Reminds me of a bad car battery, if it got too hot, car would not start for about an hour.