I've got a 2007 Arctic Cat 370 touring that has an engine problem. To start with, it has to be completely up to operating temp before it will keep running. If I take off with the usual 5-10 minute warm-up it will go for about 5-10 seconds and then die, if I flip the choke on it will rev back up and I take the choke off it will run for another 5-10 seconds. It will keep this up for the first 1/2 mile. Once it has completely warmed up it will run alright but may be lacking in power. Once warmed up when I hit the throttle at idle it will start to die so I have to quickly hit the throttle 4-5 times to get the rpm's up then it will take off. It has a single carb and both plugs are black. I am at 3,500' and I assumed the main jet was the original so I got the proper jet and it didn't help, maybe made it worse.
Your running to rich . Take apart your carb and clean it. make sure to adjust your air fuel mixture screw properly after cleaning your carbs.