before i had the passion engine i just had a mild port job with t5's, v force reeds, advanced timing, 19cc domes and an open air box. i ran a 12 tooth, yes a 12 tooth and i would kill people with 14 tooths off the line and by the time they caught me it was too late for them. i also ran a 13 tooth and that was perfect. it got me off the line quicker than shit and then i couldnt be caught. i run most of my quads with a lower gear up front becase of trails and hillclimbing. id rather have a wide range of lower gears than a bunch of really tall gears. i just dont need to be able to run like 80mph. i think if you try the 13 tooth you will like it. order a primary drive front sprocket from rmatv. they are like 7 bucks. if you dont like it you arent gonna be out much.