Quick 400ex carb question

[crfiddy04]

Ok so i bought a 2001 400ex from some one who bought it the way it is so i really have no history of motor work etc... But it has alot more torque than any of my other 400exs had. im wondering if it might have a bore kit. but with the carb, it idles at the right rpm and but just randomly cuts out and will make it stall during an idle or riding. sometimes it will just start leaking out of the overflow also. could it be that its not jetted right? or dirty? not sure tell me what you guys think. thanks alot. it also has a full big gun pipe k&n air filter with no lid on the filter box

[Toadz400]

Sounds like your carb needs to be cleaned and the float adjustment should be set. Those Big Guns give a lot of torque.

I had an '00 400EX that had way more torque than any other 400EX I rode. The engine was stock and all I had on it was a Big Gun slip-on. I even put the stock pipe back on and it still had more torque than any piped 400. I always thought that maybe I had a 440 kit in it but eventually sold it to a friend. He ended up rebuilding it and found out that the reason why it had so much torque was there was an insane amount of carbon build up inside the combustion chamber causing an increase in compression. He cleaned it, put in a high compression piston, Hot Cams, and ported it and I personally believe it has less torque than before.