hi guys i have an 03 kfx 400 that supposedly has a 440 big bore in it.. its just not fast enough for me. so would i be any faster with a 39mm carb and one of those programmable dyna ecu's? or do you guys have anyother ideas to make me faster?

 

Well if the thing is tuned right it should be pretty darn fast right now....... and by "tuned" I mean a nice full exhaust and air box mods, proper jetting and etc...etc.....

Sure a bigger carb and a new ECU will help but it might not be enough for you...... what kind of riding are you doing? Are you in the sand dunes? Or open desert? Those would be the only places I can think of where a 440 would be too slow.....

 

well i have a hmf exhaust and unifilter on with a screen kit on the air box cover.. im riding in the northwood of wisconsin..

 

The ecu will give you a little power, but a bigger carb will not always give you more power. Getting any carb tuned right is as good as any, because the motor only wants a certain amount of air and fuel. A bigger carb would need smaller jets and a smaller carb would need bigger jets.

 

yah i think my best bet rite now is to get the dyna fs and get it dyno tuned.. no need to waste big money on a carb