I'm ready to give up. My 426 really spoiled me. First or second kick every time no matter how many times it flipped, how cold it was, or what ever....This 450 takes 10-20 kicks when it is cold. Here is what I have tried: 1. 2-3 twistes on the throttle, no choke and kick. Tries to start but still takes 10-20 kicks to start. 2. no twists, no choke and kick. 10-20 kicks to start. 3. The above two with the choke and kick. 10-20 kicks to start. 4. Hot start pulled (again this is all when cold)5-10 kicks to start. The air filter is spottless along with the airbox tubes (not sure what they are called), the carb was cleaned ( brand new, it wasn't dirty or clogged ). At a fast idol, I tunned the fuel screw out 2 1/4 turns. The plug is greyish tan. No backfiring occures on deacceleration. At 1 3/4 -2 turns out on the fuel screw, the bike would run lean and backfire. All other jets and settings are factory. Even when the bike is hot, starting it is very inconsistant. Most of the time it starts up within a couple of kicks then sometimes it takes 10-20. Once running, the bike rips!! I live in south Florida, humidity is high along with the temp. Any help would be greatly appreciated!!!