I have an 03' 450 It starts fine when it is not to cold, but I use it for hunting in the colder months and first thing in the morning it is a beach to start. Once it fires up then we are good to go. The temp is probably around 35 degrees and in the mountains around 6000 feet. Like I said though once I have it started and have to restart it later there is no problem. It doesn't even try to fire untill you kick on it for 10-15 times. I choke it, then no choke, pump it a couple times, and I have had my little bro hold his hand over the pipe to hold in some of the warmer air. I don't know anything else to do, any ideas. Thanks in advance.