39,41mm fcr carb for 400ex

[Hondarider440ex]

I was wondering what would be the best carb for my 400ex. It has a 440 kit, 13:1 piston, stage two cam, curtis sparks x-6 full exhaust, oversized valves, port and polished, and I run 110 octane fuel, so I was wondering what is the best carb for my fourwheeler.

[krt400ex]

both would work well. the smaller carb will give u better throttle response and it will aid in bottom end power, and the 41mm will work better for more top end applications. depending on how ur bike is tuned is how u should make ur choice

[cals400ex]

i believe the 41 actually tapers down to the same size as the 39 so they both can fit into the air boot properly. i think that is.