13 is not real rich, its actually on the lean side, 12 would be on the rich side (the lower the number the more rich it is). Before i retuned mine after adding the K&N intake it went to 13.7, i added 4% fuel and got it down to 12.5
Thanks for this! This is something I'm going to look into, John at TI told me with the NGK's, I can run a little bit more lean to get a little more HP out of her.