I have a 1997 Mxz440 fan. It has been sitting for about 1.5 years. The reason it was sitting was the pipe gotted bent from an accident. I got a pipe from a 1997 mxz440 liquid cooled. Sit almost perfecty, but a little exhaust escaping at the top and a little louder. Anyways, I drained all the gas and put fresh stuff in. Here is the problem. It starts up and idles fine. However when I take off it bogs out and dies until I put the choke on. The it takes off and rips, runs great and has lots of power. When I let off the gas it just bogs out again and I have to flip the choke off, it gets going, but wont run without the choke on again. It will idle without it though and I need to keep flipping it on and off? Any ideas, other than that the sled still goes great, it will idle fine without dying with choke on or off.