how to fix if you are burning rich?

[MazdaAspec]

I read in one of the threads where he is smoking white and blue smoke and down in one of the posts a person said black smoke means you are burning rich. Only when driving down the highway I noticed when I gun it after driving on the highways for awhile black smoke will come out for a few seconds. Is that from burning rich or something I should not be worring about? Thanks

 

[t3t4delsol]

unless you have small black spots on your back bumper you not running rich, more then likey what your seeing is carbon deposits blowing out your exhaust when you mashing on the gas

 

[MazdaAspec]

that is what I figured. thanks