i took the air box lid off my kfx 400 and installed an outerwear. I jetted up 2 sizes from stock. I have no power, Can't even wheelie in 1st. What should i do about my jetting. I know bigger, but how much. Thanks.

 

It sounds like you are too rich now.You should not have to jet quite so rich as you did with just losing the air box lid.

 

pull your choke on when checking your settings if it clears up then you are to lean if it kills the motor or bogs then your to rich

what does your spark plug look like ?