i have a 2 seater go kart with a 13hp gx390 motor and tav2 t.c with 15" rear tires ive been tryin to figure out the best sprocket ratio using a #40 chain with 10 tooth clutch sprocket. i want to have decent top speed but also to get up and go, i was thinking of using a 40 tooth sprocket on the axle but i am open for all suggestions. any input would be great thanks.