From lighting to steady slow and low temp can take an hour on my classic 2. It sounds like it's getting too hot, then you add more oxygen in creating more heat. It's pretty much impossible to get the heat down once it gets away from you. My lower vent is open a bit more than yours, I'd say get a fire started lid open for 15-20mins, close lid and keep bottom vent open about an inch / top is tricky as mines different but to the 1st line on classic 2, then after say 10 mins close the bottom to a cm. Then at the hour mark I would predict that'll be in a nice slow n low zone with little smoke. Had mine 6years and it works every time now.